The Unquantifiable Variable
by BeckyS
Summary: Can Don Eppes do his job when one of the hostages he has to rescue is his brother? A case story in 8 chapters plus an epilogue, with multiple posts per chapter.
1. Chapter 1, Part 1

_A story in 8 chapters plus an epilogue.  
I'm posting the first chapter in its entirety (three sections),  
then we'll see how it goes from there.__**

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**_

**The Unquantifiable Variable**  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. With grateful thanks to all of the creative minds behind the show, as well as to "M" for her beta and Mac for the math that is the underpinning of the story. He took my initial idea and explained and expanded until the story took wing._

_**Chapter One, Part One**_

Charlie Eppes was surprised to discover that he was happy.

It wasn't that this was a new or particularly unusual feeling for him. The sheer pleasure of creating a new equation was glorious, and making and having dinner with his father satisfied something deep inside. And when he finished a project with his big brother and Don grabbed him at the neck and squeezed gently, the world was darn near perfect. This, though, was different.

What was so odd about it was that he – the math prodigy of CalSci, a full tenured professor for over three years (even though he hadn't yet reached thirty), a man courted by the NSA, the CDC, the FBI, and several other alphabetical organizations for help with their most difficult problems – he, for the first time in his life, was having a wonderful time simply browsing in a store.

It wasn't that he never went shopping, but that was usually an exercise in efficiency. He'd discover that he needed something, figure out which store to go to, head for the right aisle, pick out the right item in the right size, make the purchase, and get on with his day. He had loved shopping for clothes with his mother – she knew places where clothes were simply and comfortably cut, but were made from fabrics woven with the most interesting patterns. Then there were the few stores where he'd get lost – in his head, that is – and not come out for hours. Those tended to be places that were full of intricate gadgets. He could remember being caught by surprise by a frantic roar from his father on a shopping trip when he was eight. _He'd_ known where he was, in front of what he'd later learned was called a "Newton's Cradle" – a 5-ball pendulum-type setup that demonstrated the conservation of momentum – and hadn't understood what the fuss was about.

Neither had Don, as he recalled with a grin. There were days back then when Don would have been happy to permanently lose his little brother. Sixteen-year-olds simply were not equipped to handle a brother half their age who could do their high-school homework with ease. While Charlie's particular expertise was mathematics, he generally aced his other courses as well since his parents wouldn't allow him to work extracurricular math projects until his homework was done, and would cut him off completely if he brought home less than a B. Not that his brother was exempt from the requirement for good grades, either. They knew he had his share of intelligence as well, and they'd cut him off from his beloved baseball for a C.

Charlie wandered down another aisle and stopped in front of a display. So many choices . . . would his father like this color? Or maybe that one? Technically, it didn't matter. It was his life, his money and – even his brother agreed – his decision. But if you could drag Charlie's attention away from whatever problem he was working on long enough for him to notice the world around him, he simply _couldn't_ make a decision that would upset his father. Not when he could avoid it. There had been too many times he'd hurt his family over things he couldn't control.

He held two of the pieces of thin card stock up to the light. The store had big plate-glass windows along the front, and someone had placed all the merchandise that needed a bright, clear light nearby. He cocked his head to one side and squinted at them, trying to decide if there really was a color difference, or if it was simply the material they were made of that made them look so different.

"Havin' a little trouble there, Charlie?"

"These are the same?" he asked.

The store's owner and manager, Benito Mendez, peered at the two slips of colored paper and stroked his luxurious white moustache. "Depends. Same color, but different finish. Which one you want depends on what you're gonna do. If you're gonna paint a bedroom wall, you want this one. Gonna do furniture or some surface you gotta wash all the time, like a bathroom or kitchen, you might want the other." He raised an eyebrow at his young friend. "You ain't gonna paint the outside of that house of yours, are you?"

"Stain rather than paint – Pasadena Heritage wouldn't let me do anything else. But, no, I'm not ready to take on that project. One step at a time, just like you said. Though I'll have to do something soon. Dad said it's been about ten years."

Benito chuckled. "Handy, havin' the previous owner around to tell you when and what things was done."

Charlie grinned. "Dad didn't realize what he started that first time he sent me to the basement to work on the heater."

"Bet you didn't either."

Charlie ran his eyes over the neat rows of paint samples. Their order appealed to him. They were all neatly stowed in their slots, arranged from left to right by hue, top to bottom by intensity. "No . . . no, I didn't." On impulse, he added, "Don and my dad are always telling me I need to get out into the world more, get my head out of the classroom, away from the chalkboard and computer."

"That's mostly good advice." The old man paused while he took off his glasses and held them up to the light. He pulled an embroidered linen handkerchief from his pocket and used it to rub the lenses clean. Only after he'd finished his routine did he turn back to his customer. "You're a bright young fella; what's been keeping you from following it?"

"Well, I only have so much time." Charlie suddenly realized how that sounded. "No, not that! It's just that mathematicians do their best work when they're young. I've learned everything I can as fast as I can, because I know it won't be too long before I won't be able to see things as clearly, won't be able to make the connections, find the answers."

He pressed his fingers against his temple as if the pressure would help him put his thoughts into words. "Not that it's always easy now, but my mind – it's sharp. It's ready. Sometimes it's so full of thinking that I feel like I'm riding on the top of a speeding train, seeing and understanding and absorbing everything that goes by. I know I'll lose that someday." He stopped suddenly and shrugged as if it wasn't important.

Benito wasn't fooled. He saw all kinds of people – Pasadena had a large number of early 20th century Craftsman-style houses, along with their owners who tended to get involved in projects that required hardware stores. While this mop-headed young man was surely the most brilliant of his customers, he wasn't the most obsessed. He'd seen the same fear in other eyes, and less warranted. "Y'know, son, we all slow down as we get older, but most of us don't notice until we get up out of bed one day and find out the bones are gettin' a mite creaky. It's just that, when you got work as delicate as you do, you see it sooner."

Charlie felt the sharp edges of crumpled pasteboard against his palm. He hadn't realized he'd crushed the sample cards and tried to flatten them back into their original shape. "I don't want to do anything else," he muttered. "I've never wanted to do anything else." He looked up, and he felt the fire of his passion for mathematics rise up inside. "It's me. It's who I am, who I've always been."

Benito slapped him on the back. "Change comes to all of us, but it don't have to come to you yet, an' when it does, it don't have to be a bad thing. You got a choice – you can take it on or you can mope about it, but it's gonna happen either way. Think about it, though. Would it really be so bad to find a nice young lady someday, settle down to raise a few curly-headed math geniuses – or maybe a doctor or a piano player, or who knows what?"

Something inside Charlie relaxed, and a grin teased at the corner of his mouth. "No, that wouldn't be so bad."

"So go look at the new wrenches," he laughed, "and don't worry about tomorrow until it comes."

Charlie nodded and tucked the two color samples in his pocket. He headed back to aisle 23, his thoughts turning over what the wise old man had said, balancing the present against the future. _No_, he mused with a slow smile, _that might not be so bad at all.

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	2. Chapter 1, Part 2

**_The Unquantifiable Variable_**  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter 1, Part 2_**

Don Eppes eased his aching body into his chair at the FBI's Los Angeles office, grateful he was wearing his jeans and a comfortable pullover, and could slouch without worrying about wrinkling his clothes. His partner, Terry Lake, leaned against her desk, facing him, still dressed in one of the casual long-sleeved knit tops and the flared-leg jeans she preferred for after-hours work. He rubbed his eyes with a futile hope that she wouldn't continue her argument.

Their argument.

No; hers. He was too tired after an all-night stakeout to argue.

How had he ended up posing as the wine-soaked bum crashed in a stupor against that torture rack of a dumpster, while young, strong, flexible David was in the comfortable air-conditioned van with all the listening equipment? He knew the answer – he'd been the one who set it up that way. He preferred calling the shots, but this job had been pretty straightforward, and he'd figured David needed the experience behind the scenes. He'd kept override privileges via the headset hidden under the smelly flap-eared hat he'd worn, but otherwise had let David run the show. The operation had gone off without a hitch, reaffirming his confidence in the young agent, but it had taught him something, too – it wouldn't be all that many more years before he'd be too old for the stakeout business.

When after a few moments Terry still hadn't spoken, he looked up. She merely raised an eyebrow at him. He sighed in exasperation. "Look, I know you're right, I'm just too whacked right now to _want_ you to be right."

A pixie gleam lit her dark chocolate eyes. "So if I let you get a ten-minute nap, you'll take care of it?"

"Twenty."

"Fifteen."

"I'll take it." He sank down farther in his chair and closed his eyes. He heard her talking in a low voice to someone, then what seemed just a moment later, smelled something wonderful under his nose.

"Coffee," he mumbled.

"Fresh from Bianca's Bakery," he heard David say.

His eyes wouldn't open. "It hasn't been fifteen minutes yet."

"Actually," the younger agent said, "Terry said it's been twenty."

He sighed and gave up. He straightened in the chair, looked blearily around until he located the bright red cardboard cup that David had been waving in front of him, and welcomed its warmth to his hands. A single sip of the steaming hot brew brought his mind back into focus. The extra five minutes had been just what he needed.

David smiled sympathetically and leaned against the opposite desk. He was back in a suit, and his sleepless night didn't show at all. Somehow, Don pondered, he never looked rumpled. It was a good trait in an FBI agent, to always look cool, collected and in control, even if you weren't, but Don wondered sometimes how the younger man did it.

"Where's Terry?" he asked, taking a second sip.

David gestured at the two cups on the desk behind him. They stood next to a pile of the fresh fruit filled pastries David had introduced to the team, to their communal delight. "After I got back with the coffee, she headed for the interrogation room to see what Joe was able to get out of our new friend, Martin. Left me on guard duty."

"Guarding me?" Don huffed.

"She said the pastries, but I got the message. We all had time to rest yesterday before the stakeout while you were still working with Charlie. No one came by that had anything that couldn't wait. I would've woken you up if they did."

Don selected one of the pastries that had thinly sliced fresh peaches layered on top. "Mmm," he mumbled and chased it with a larger swallow of coffee. "Sure wish Bianca would open a bakery out my way. Or even near Dad's, like at that little shopping center around the corner."

"Arroyo Plaza?" Now it was David's turn at the pastry tray. His hand hovered between the blueberry and the cherry. "The one with the hardware store, next to Arroyo Savings and Loan?"

Don laughed. "Even you know about Benito's?"

David looked skyward. "They not only have tools and hardware, they have paint and grass seed and lawn furniture and—"

Terry strode in and slipped a hand under David's, snatching the blueberry pastry.

"Hey!" he protested.

"Plenty more," she mumbled around a mouthful. She unremorsefully swiped a crumb from her lips and waved him away from her desk.

He shook his head at her and took the strawberry pastry, but didn't move.

Don noticed that he didn't look too put out. He grinned. "Gotta be fast around her, David. Gotta be smart." He turned to his partner. "So, what've we got?"

"Well, Martin says he's got kind of a silent partner. Doesn't know who he is – gets instructions via email, payments at different drops. Fred from the lab is taking a team over to his apartment to confiscate his laptop, but if this partner is as smart as we think he is, we'll be lucky to get anything off it."

"Email from one of the major free services, sent from public locations," David guessed. "Nothing to tie him to the mob."

She nodded. "He probably sends them from libraries, coffee shops, the mall – any place he can find a wireless hot spot. The emails tell Martin what to do next. One email, one step. Anything goes wrong, he doesn't know any future plans."

Don scrubbed at his face. "There should be information in the email headers that'll tell us which ISPs they were sent through, then we'll have to get a warrant to get those companies to release the data on the sources."

Terry nodded. "We can do it while you get some sleep, Don. I'll call you when we have something for you to look at."

"Something for Charlie to look at, you mean." He yawned.

"Mmhm. Do you know his schedule today?"

He stood up and stretched, his body telling him it had been too long from the sack. "Free this morning, a couple of classes midday, then office hours later this afternoon for students he's advising. He doesn't like to cancel those, but he can."

David figured the timing and said, "Probably won't need him until this evening or tomorrow anyway. By the time we figure out which ISPs we need to talk to, get a judge to issue the warrant and then get the data from them, I'm sure he'll be finished with his students."

Terry wadded up her napkin and threw it in the garbage can. "Then the best use of your time, Don, is to get some sleep while you can. Let Charlie know we'll need him, and then check back in when you wake up."

"I'll go crash at the house – be easier to bring him in with me."

David studied him with a slight scowl. "You okay to drive?"

"Hey, I just had a twenty minute nap and some of the best food on the planet. I'll be fine." He slipped a couple of bills from his wallet and laid them on Terry's desk. "And whether or not you were right about whose turn it was to pay for Bianca's, thanks for the nap."

An impish smile lit her face. "You're welcome," she said as he walked to the elevator.

"So," said David. "Whose turn was it really?"

She just waggled her eyebrows at him.

And at the Arroyo Savings & Loan, a teller stepped on her silent alarm button.

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	3. Chapter 1, Part 3

**_The Unquantifiable Variable_**  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter 1, Part 3_**

Charlie had worked his way over to the PVC department, slipping past a tall, well-built man with the tan and bleached blond hair of a surfer, but rough hands that made construction a more likely profession. The physical contrast between the two of them was almost trite – the power of the body versus the power of the mind – but the man nodded to him in passing, kindred souls in search of just the right pipe. Charlie nodded back, feeling the unexpected warmth of belonging to a world he had never really acknowledged, even if he'd known it had to exist.

He didn't need to replace any piping at this point – at least he hoped he didn't – but even so, the myriad pieces pulled at him with some strange fascination. Elbow fittings in perfect 45 and 90 degree angles; three-way connectors, four-way, five-way and cross connectors; pipe snaps, pipe caps and slip T fittings. The half inch pipes that filled the bin in front of him had an outside diameter of 0.840 inches, he read off the label, yet the next sign over said the diameter of the one inch size was 1.315. Why was the one inch pipe .0125 inches thinner than the half inch? He picked up one of each and examined them. They looked the same to him, but then he didn't have a measuring tool with him. Of course he could find one here in the store, but instead he cast around and picked up a one-and-a-half inch pipe that said its outside diameter was 1.900 inches. Well, at least that made sense – the thickness of the bigger pipe was .05 inches more than the half-inch. More fluid going through, more pressure, thicker pipe walls?

He knew he could find out, but maybe Larry knew. His friend had said often enough that restoring his beloved nineteenth-century Victorian home was a welcome break from the intensity of thought needed for his ground-breaking physics projects. Something about the soothing repetitive movements of sanding floors or the mindless labor of painting scrollwork.

He picked up one of the elbow joints and slid the right sized pipe into it. It fit perfectly. Everything here would fit together perfectly to make – what? At this point, he didn't know and didn't really care; it was the simple fact of unending possibilities that fascinated him. There were bins of the shiny white piping stacked in perfect pyramids, rows of joints lined up side by side with their open ends looking like a series of zeros that tried to measure infinity, shelves of trays marked on the outside with mysterious drawings and "1/4 inch" and "5/8 inch" and even "2 mm." What could you build with all of this? What couldn't you build?

"Piping, Charlie?" came a voice from behind him. "Are you sure you're ready for that?"

He turned to see Solana Mendez, Benito's daughter, grinning at him.

"Nope. I know when I'm out of my league. I just couldn't resist wandering around."

She tilted her head to one side. "Want a cup of coffee while you look? I just put on a fresh pot."

That personal touch was what he really loved about this place, even more than all the marvelous secrets on the shelves. The Mendezes knew everything about every piece of merchandise in their store, but more than that, they shared their knowledge, their love of building things, and they shared themselves with every person who walked through the doors. It also didn't hurt that they were an easy bicycle ride from his house.

_His_ house. No longer his father's, that he lived in. He hadn't been able to bear it when his father had started talking about selling it. He knew they all needed to move on after his mother's death, but even if his father and brother were ready, he'd discovered he wasn't. Just the thought of losing the house had shaken his whole world.

So he'd bought it. After getting over the surprise, his father had laughed in delight at Charlie's logic. He would continue to live there, rent-free as Charlie had for his whole life. They both knew, though, that there was more to it than a financial exchange. Accepting the deal had been a tacit acceptance by Alan Eppes that his youngest son was still grieving, but he'd used the occasion to encourage him to move on by telling him he was looking forward to having children underfoot again. Charlie had simply grinned and kept his thoughts to himself.

So now he was contemplating having to replace the plumbing someday. He decided that when that day came he'd make sure he was able to do it, but for now, coffee with Solana sounded good. He glanced at his watch – he had almost an hour before his first class, his only undergraduates. It was a subject he knew intimately and one he was good at teaching, so he knew he could skate in at the last minute if need be.

He suddenly realized she was still waiting for an answer. "I'd love a cup. That's really why I come in here, you know."

She laughed and led the way to the front of the store where a restaurant-grade machine sat in front of one of the two registers. Styrofoam cups were tucked between boxes of school supplies and a hanging display of micro-flashlights. He eyed them as he poured himself a cup of coffee. They were on keychains, and could be adjusted from a wide circle of light to a fine beam.

"I could use one of these . . . ." he murmured. "Then when I'm in the back of the classroom working with a student, I could talk about specific points in my equations up on the blackboard."

"Just don't shine it in someone's eyes, especially on tight beam. They're bright enough to do some damage."

Charlie twisted the end, and the beam grew wide. "Huh. If I'm riding my bike home after dark and drop something, I'd have it right there to help me find it."

"That's what we're all about," said Solana. "Solutions to problems you didn't know you had."

"I like that." Then he raised an eyebrow and quirked a grin. "Now if you could just show me the aisle that has the solution to P versus NP . . . ."

She slapped him lightly on the arm. "_Hardware_ solutions, Charlie. _Hardware_." She looked up to see an older black woman with steel-grey hair dragging a little girl by the hand to the register, the other arm carrying a plastic shopping basket. "Let me know if you need anything else, okay?"

He watched the little girl for a few moments, noting her fascination with the cash register. He smiled, sensing a kindred spirit. Maybe his own children would be as cute? He laughed at himself – he really preferred to get married before having any children, and he was a long way from being able to make that happen. Once Amita finished her doctorate, maybe he could start exploring that intriguing relationship . . . .

His eyes dropped to the flashlight in his hand, and he started experimenting with the tiny pointer light. He tested it by shining it on the floor and the ceiling, with the narrow beam and the wide, then checked all the different colors of cases. He had just decided on green when a woman's scream ripped through the store.

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	4. Chapter 2, Part 1

_With thanks to the few who dug around and found the first three sections so very, very quickly, and then wrote up reviews to let me know. Your appreciation means so much. And Sabrina, your comment in particular cracked me up -- what a temptation!_**_

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_**

**_The Unquantifiable Variable_**  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Two, Part One_**

Don steered the quarter-ton black Suburban through the L.A. traffic with the ease of long practice. His mind drifted to the first time Terry and David had ridden in it together. It was an expensive vehicle, but he figured it more than paid its way by being able to haul some of the heaviest equipment the FBI needed for field work. Terry'd had a field day watching David play with all the manufacturer's gee-whiz gizmos. She thought it was funny that he was more intrigued by the Chevy gadgets than any FBI gear they had access to. Don was simply glad that she'd decided not to share her psychological analysis of David's preferences beyond a muttered _Boys and their toys._

He was brought abruptly back to the present by a siren behind him. Heart thumping, he checked his location: about a mile from his father's – _no, now it was Charlie's_ – house. He pulled to the side, shaking his head at the small sports car ahead of him that had decided to try for its turn before the official vehicle caught up with it. The police car passed him then slowed, hampered by the obnoxious driver, and accelerated quickly once there was even minimal space. As people do, he wondered idly if the policemen were headed toward his own destination and felt a small jolt of relief when he saw the patrol car pull into the parking lot of the small shopping center. _Probably something going on at Varieties,_ Don thought. The bar had been open for about an hour; it wouldn't be unheard of for someone to get one drink too many under their belt, even this early.

The honk of a horn from behind brought his attention back to the road, and he realized that the light in front of him had turned green. He swore softly at himself – he was tired. That was the second time in ten minutes his mind had drifted. He checked the time on the dashboard: 11:08. Charlie had mentioned a noon class, so he might even catch him at home; let him know they'd be needing him later.

As he drove past the stores, although his thoughts were already on the bed in his old room, he automatically cataloged the location the police were interested in. Benito's Hardware. He hoped everything was okay, that it was nothing more than a shoplifter. The Mendezes had run the hardware store since he was a kid. Walking through the aisles still brought back memories of shopping trips with his father.

He forgot the policemen as he parked on the street in front of the family house and walked across the grass to the front door. His father's car was in the driveway, but he could see into the open garage that his brother's usual parking place for his bike was empty. Oh, well. Charlie must have gone to the university a bit early. He'd catch up with him later.

"Hey, Dad?" he called out as he came through the door.

"Donnie?" his father answered. "I'm in the kitchen." He turned from rinsing lettuce in the sink when Don entered. "Want some lunch? I'm making a sandwich for your brother – not that he'll remember to eat it."

Don rummaged around in the refrigerator and pulled out a can of soda. "Yeah, I could use something to eat. We were up all night, just finished up about an hour ago."

"So I see," Alan said, gesturing with a table knife at his son's rumpled clothes before dipping it into a jar of mayonnaise. A few quick swipes and the sandwich was ready. He slid it onto a plate and handed it to Don.

"I thought this was for Charlie?" Not that he was going to turn it down. The smell of the bread alone reminded him of how hungry he was.

"You're here, he's not. I'm sure I'll have time to make another one before he turns up." Don was, in fact, already settled in his chair and taking his first bite. "At the rate he's going, he'll have to ask you for a ride so he isn't late."

Don took another swig of soda, washing down the first delicious mouthful. "Where'd he go?"

Alan cut two more slices off a tomato and placed them on the lettuce leaves. "Said he wanted to pick a couple things up before class, something about flexible whiteboards." He shook his head. "Not enough we have blackboards all over the house, now he wants to glue whiteboards around corners. I wish Benito would sell shares—" He stopped suddenly, staring at his son. "What? Something's wrong with the sandwich?" He sniffed at the jar of mayo.

Don's sandwich had fallen to pieces on his plate. "Benito's Hardware?"

"Of course, your brother won't go anywhere else if he can help it. Donnie, what's wrong?"

Don reached for his cell phone, just as it rang.

"Eppes," he answered, his voice clipped.

"It's Terry," his partner answered.

"What's up?"

"L.A. police called in on a robbery in your area. I wanted to let you know, so you can tell your family to keep clear."

"Where is it?"

"They hit the savings and loan at Arroyo Plaza—"

"The savings and loan?" he interrupted, relief flooding his body.

Alan had set the sandwich makings aside and was listening carefully. "Robbery?" he mouthed at Don, who nodded back.

"More than that," Terry continued. "The gunmen have holed up in the hardware store. The police say they have hostages."

"Oh, my God," Don moaned.

"Don?" Terry's voice was strained.

"Charlie—" he choked. "Charlie went to the hardware store. He's late getting back." He felt the weight of his father's eyes. He nodded slowly, saw the same fear he felt growing on his father's face. "I can be there in four minutes. Tell them to expect me."

"Don, you're off the clock, and we already have a team on the way."

"But I'm closer. You tell them."

He didn't hear her answer because his phone was already back on his belt and he was on his way out the door.

Alan followed him, grabbing at his arm. "What about Charlie? Don, tell me about Charlie!"

"Dad, I don't know. I gotta go find out. Wait here in case he comes back. If he isn't here in five minutes, call Amita, let her know he won't be making his class, then get her to come over."

They were nearly at Don's car. "No. I'm coming with you."

Don turned back and put his hand on his father's shoulder. "You can't, Dad. This is official business now. You know I'll do everything I can."

"Yes, yes, I know you will, but I'm not sitting here at home—"

"Then get Amita to bring you over." He climbed up into the Suburban. "I hope Charlie's already on his way home, but if he's not, I don't want you alone."

Don turned the engine on and his scanner immediately crackled. Out of all the formal, stilted words, both heard ". . . shots fired . . ."

Alan swallowed, his grip on the door turning his knuckles white. "If he'd been on his way home, you would've seen him, wouldn't you?"

Don stared at his father for a brief moment, then whispered, "Yeah." He shifted into gear and burned rubber down the street.

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	5. Chapter 2, Part 2

_Thanks to Freefall and Patty for commenting on individual sections; it's nice to see repeat names! Steph, I'm going to be updating this one pretty fast -- it's complete, and I think it needs to be read without huge waits. Knadineg & Patty, I appreciate the detail in your reviews. It's always nice to know what grabs people. _;) _These next two parts finish Chapter 2. Hopefully I'll get Chapter 3 formatted tonight or latest tomorrow morning._**_

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_**

The Unquantifiable Variable  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Two, Part Two_**

When the woman screamed, Charlie dropped everything he was holding and whipped around to find out where she was. He saw a flash of movement at the front doors, then two men came barreling through the double entrance, one holding a bag, the other hauling the little girl Charlie had just seen at the checkout.

The man with the bag was looking behind him and ran straight into Charlie, knocking them both sprawling into a display of power tools. Charlie scrambled to cover his head with his arms, but was too slow to block a router from striking his forehead, dazing him and leaving a nasty gash. His left leg exploded with pain when a circular saw landed on his knee. He bit back a cry of pain and simply endured until everything had finished falling.

"Rick!" he heard. "We gotta get outa here!"

Someone nearby moaned.

Charlie lifted his head carefully and looked around. The man who was yelling still had the little girl tight against his side with one arm, a pistol waving through the air in the opposite hand. The man apparently called Rick was crumpled on the floor under a pile of bags of concrete mix, and a bag of cash had split open, bills scattered across the floor. It didn't take a genius to figure out that two bank robbers had just chosen the wrong escape route.

The old woman fought to get back in the front door. "Leeda!" she cried – a long wail of anguish – and the man holding the girl spun and fired at the doors, shattering a pane of glass in one door and drilling a hole in another.

"Grammy!" screamed the girl as she fought furiously to get free.

Charlie sat up and tried to gather his scattered wits, just as the construction worker he'd met in the PVC aisle bulled through the mess.

"Leave the girl alone!" the man yelled.

The gunman whirled and fired again. Charlie ducked instinctively, but the girl's would-be savior wasn't so lucky. He landed in a heap right next to Charlie.

Charlie looked around at the wreckage. He'd just been looking at flashlights, sipping his coffee, and now there was chaos everywhere – injured people moaning, a little girl sobbing in terror. He looked down at his own leg, saw the rip in his jeans, the blood welling from a deep cut just above his knee.

"Get up," the gunman ordered, his voice raspy and harsh.

Charlie blinked at him. "What?"

"Up," the man repeated, pointing with his gun.

He climbed to his feet and stood shakily amid the wreckage, weight on his right leg. He looked around, took in the sobbing child, the ominously silent construction worker, the moaning robber who was still buried under the display wall and the shocked faces of Benito and Solana as they held each other. The gunman stood before him, his face distorted by a nylon mask, chest heaving as he breathed heavily.

"What . . . ?" Charlie asked, his thoughts still scattered. "Why . . . why would you . . . ?" He pressed hard against his temples, trying to try to bring his mind back into order. He looked up at the gunman and saw the wavering pistol. Could the man be as terrified as he was? This wasn't good.

Charlie consciously lowered his voice, trying to calm them both. "This isn't going to get you anywhere. Your friend is hurt, and so is this man. We have to check them, see if they need help."

"No." The gunman waved the pistol at Charlie again. "Get a sack for the money first."

Charlie raised his hands in front of him, showing that he wasn't any threat. "Solana can do that while you look after your partner. If you give me the girl, then you still have one hand free to help him."

The man glanced over at Solana. "Do it," he ordered.

The girl, perhaps feeling that this gentle stranger was safer than the man who'd taken her from her grandmother, leaned towards Charlie, her arms outstretched. Tears still tracked down her dark cheeks, but her sobs had settled to hiccups.

Charlie wanted to reach for her, but realized he had to go slowly. "You can't hold the gun, the girl, check on your partner and take the money," he said in what he hoped came out as a reasonable tone. He could hear Solana behind him, dropping wads of cash into a shopping bag, but he kept his focus on the gunman. "We aren't going anywhere – I can barely walk, anyway." He hobbled forward a step, locking his left knee in a slight bend that minimized the pain as much as possible.

The gunman slowly loosened his hold, and the child wriggled free. Charlie knelt as best he could, and in two jumps, she was in his arms. "It's all right," Charlie soothed. He tucked the girl's face against his shoulder and stroked the back of her head. The springy black curls were soft against his fingers. "It'll be okay, I promise."

He wished he knew how he could possibly keep his promise.

* * *


	6. Chapter 2, Part 3

**_The Unquantifiable Variable_**  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Two, Part Three_**

Don flashed his badge at the policeman guarding the yellow tape at the scene, and searched for the center of activity. He automatically noted that both an outer and inner perimeter had been established, as well as the beginnings of what looked like a command post. A frantic gray-haired black woman was being gently but forcibly held by another police officer safely behind a van while a female officer tried to question her. An older black man in a silvery-gray suit stood off to the side. Don kept his badge in hand as he approached. "Special Agent Don Eppes, FBI," he said softly. "My office said you called for us?"

"Detective Tom Nolan, LAPD." He led Don a few steps away, still keeping the van between them and the scene. "Two men robbed the savings and loan, then ran into the hardware store." He tilted his head in that direction. "Her granddaughter is still in there. They grabbed the girl on the way in, shoved the woman out the door. Two shots have been fired, but we don't know if anyone inside is hurt."

Don grimaced. "Do you know how many hostages?"

"Can't get anything out of her." He shook his head. "Not that I don't sympathize – I've got a granddaughter myself. It doesn't help us, though." He looked around, searching the lot. "You're the only one? I thought you Feds sent teams out."

"I was just around the corner – the rest are on the way." He rubbed at the back of his neck and looked over at the woman. "Let me try?"

Nolan raised an eyebrow. "As long as my people hear it, too."

"No problem," Don said. "What's her name?"

"Alana Gibson. The girl's name is Leeda."

"Thanks."

He studied the woman as he approached, noting she was still trying to get loose from the policeman. She was all of five feet tall and maybe fifty years old, but she fought him like a tiger.

He held out his badge. "Mrs. Gibson? Don Eppes, FBI."

She turned her head slightly toward him. "FBI?" she asked bitterly. "And what are you going to do? Tell me, like them, to just sit here and do nothing while my Leeda is inside?"

She reminded him forcibly of his father – hadn't he just had a similar conversation with him? "No, ma'am, I'm not. I know you're worried about her. I'm going to ask you to give me as much information as you can, so we can get Leeda out. I need you to tell me just exactly what happened."

"I told these folks a man ran in and grabbed my granddaughter and then shot at me."

She tugged again, trying to get her arm loose, but at least she was talking to him.

"How many shots, Mrs. Gibson?"

"How many—?" She stopped pulling and finally gave him her full attention. "It was . . . it was one. Just one."

"How many men?"

"Two. The tall one shot at me. He—he shot at me." Her eyes opened wide and she suddenly swayed.

Don caught her around the waist and nodded at the two officers, who moved back to talk with Nolan. She looked like she didn't have the strength to take a single step. He guided her to the open side of the van and eased her down to sit on the step to the van. "Mrs. Gibson," he said, trying to get her attention. He crouched squarely in front of her. "Mrs. Gibson, tell me about Leeda."

"She's seven. Just seven years old." She raised her eyes to his. "She's my son's daughter."

"Okay. I want you to know that we're going to do everything we can to get her back to you safely."

She looked at him, lost. "I just wanted to get some new knobs for my dresser. I was taking Leeda back to her mother and I was only going to take a minute." She grabbed his arm, hard. "Why would they take her from me? Why?"

"Mrs. Gibson, I don't have an answer for that yet." He suspected the robbers had acted on impulse, knowing that all law enforcement officers would think twice about firing a weapon when there was a child nearby. "I know this is hard, but I need you to help me. I need you to tell me what happened; I need you to tell me what you saw."

Her breath hitched, but she regained control. "Yes. Yes, I'll do whatever I can to help."

"Good," he encouraged. "Anything you can tell me might help get Leeda and the other people back. Tell me what you saw."

"The other—? Oh." Her focus suddenly shifted and she frowned. "Yes, there would be others. There was the cashier, a sweet girl. I think she's related somehow to the manager. They look a lot alike. He was there, too. I remember seeing him coming out of his office." She glanced up.

"And?" he asked. "Who else did you see?"

She nodded. "There were two young men, one tall and blonde, looked very strong with big muscles. He looked like he was in his twenties. I saw him over in the piping section, over on the left side of the store. The other man is shorter. Thin. He has curly black hair and the sweetest smile. He was up front by the cash registers."

Don felt his heart sink. "Did you hear any names, ma'am?"

She shook her head. "I wasn't in there very long."

"Do you know if they left before you?"

She shook her head, watching him carefully. "I don't know about the taller man, but the young one – he was still deciding on a flashlight while I paid." She paused and leveled a keen gaze on him. "You're going to get them out, aren't you." It wasn't so much a question as a statement.

Her utter faith in his abilities shook him. "Mrs. Gibson, the only promise I can make is that I will do everything I can to get Leeda back to you."

Her eyes filled, but she blinked them back. "I'm not asking you for a miracle. I'll be saying my prayers for that. But you seem to me to be a strong, resourceful sort of person. I think you'll do as well as anyone could."

He took her hand and squeezed it once, gently, then stood. Eye to eye, they made their promises. He, to do everything possible; she, to have faith in him.

"Detective Nolan," he called.

The LAPD officer broke off from his discussion with his team and waved him over. "What did she say?"

"At least five hostages. The owner, Benito Mendez, Hispanic, about fifty-five with white hair and a white moustache; his daughter, Solana, who's twenty-five years old, five foot seven or so, hair just below her shoulders; two men, Caucasian – one big, tall, blonde, maybe twenty-five; the other not that much taller than Solana," he held out a hand at about his eye level, "twenty-nine with longish, curly black hair and dark brown eyes – and the little girl, seven years old."

Nolan whistled. "I'm impressed. She told you all that?"

Don shook his head. "She told me who was in there. I know the Mendezes. I grew up a few blocks away, and he's had the store a long time. My family still lives here – that's how I got here so fast. Do you have a description of the suspects?"

"Not much. We have the film coming from the savings and loan, but in the meantime, the teller said they were wearing nylon masks, so all she could guess was black hair for both of them. One was tall and thin, but looked strong; the other was short and compact. The short one told her he had a gun in his pocket, but what scared her was what she thought were wires under the taller guy's jacket."

"Wires? Explosives?"

Nolan hooked his thumbs in his pockets and sighed. "She's not sure – just going by what she's seen in movies. She's knows it might not have been real, but didn't want to take chances."

"Smart," Don nodded.

"I've got men checking every car in the vicinity. They're running the plates on them, checking them with DMV. As soon as we get some names, we'll pass them on to your people."

"Good – we'll see if we can come up with anyone who has a record with us." Don looked around and saw that his team had finally arrived, though as unobtrusively as possible so as not to alarm the gunmen. They hadn't used sirens and had parked out of sight, but they were here, flak jackets and all. Terry had an extra in her hand – his.

"Terry, David, this is LAPD Detective Tom Nolan. Detective, Agent Lake and Agent Sinclair."

"The rest of the team is on their way," Terry said. "There's an incident at LAX, so we're drawing people and equipment in from all over the city." She angled away from them, drawing Don with her body language. "Fill me in?" she suggested.

David took the hint and drew Nolan back to his men, asking about the layout of the stores so they could position their snipers in the best possible locations. Terry and Don walked over behind his car to speak in private.

"Charlie?" she asked.

"Yeah, I'm pretty sure he's inside."

"Oh, Don! Do you know if he's okay?" She glanced at the storefront. "Does your dad know?"

"He's on his way over. I made him wait at the house to make sure Charlie didn't turn up, and Amita's gonna bring him. We don't know if the hostages are okay; there were two shots fired. One took out one of the front windows, but we don't know where the other one went. They haven't tried to contact us so far, and these guys don't have a command post, so we haven't been able to figure out what's going on in there."

"Well, we can take care of that as soon as our CP gets here," she answered.

"Yeah." He rubbed the back of his neck in frustration. "First things first, get more information. And we try to set up communications with them, get them talking to us." He paused. "And Nolan—"

"Let me guess. He doesn't know one of the hostages is your brother?"

"No."

"We have to tell him. We have to use every bit of information we have, and Charlie's a big variable."

Don ran his hand through his hair. "I know. But I don't want him yanking the operation out from under us just because my brother is in there."

She stepped in front of him and grabbed both of his arms and stared him straight in the eye. "Don, I have to ask – are you okay with this?"

"No," he said, leaning wearily against the car. "I'm not. That's my brother in there, someone who shouldn't have to deal with this kind of thing, someone I'm supposed to be protecting – so he can scrawl stuff I'll never understand on his blackboards and teach kids to solve problems that'll make the world a better place. Maybe even a place where people like us aren't needed so much. Damn it, Charlie belongs inside those ivy-covered walls, in those weird buildings, in an ivory tower where everything can be measured and evaluated and fit into its own little corner – not out here in the real world, this filthy place where people can get killed—" He cut himself off and took a deep breath, trying to calm himself. "I'm sorry."

"You needed to say it, to get it out. No need to be sorry." She handed him the vest. "Now you can concentrate on your job. Right?"

He heaved a sigh. "Yeah. Yeah, now I can get on with it." He slipped into the vest and set his mind on the job to be done. "C'mon. Let's get the command post set up."

* * *


	7. Chapter 3, Part 1

_AN: Two more parts this morning, for a complete chapter. Alice, thank you for the detailed reviews; as I've said before, it's very helpful and gratifying to know what catches your attention. As for Charlie not being helpless or a wimp in this fic, I've always seen him as a rather resourceful sort of person, just somewhat out of his depth as he moves into Don's world. One of the fascinations about the character, for me, is how he copes. Thanks to those who've contacted me privately, as well -- you know who you are, and I appreciate you taking the time and effort._**_

* * *

_**

The Unquantifiable Variable  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Three, Part One_**

Charlie sat on the floor near the construction worker, who still hadn't moved. The gunman had tossed him a chamois from a nearby rack, and he'd tied it around his leg to try to stop the bleeding. He thought it was working, because the red-brown had stopped leeching through the tan material.

The little girl sat in his lap, her arms wrapped around his neck. He'd tried getting her interested in drawing on one of the many pads of paper that were strewn on the floor, but while she watched his scribblings, she wouldn't let go of him long enough to pick up a pen herself. He'd gotten her name out of her, but nothing else. He found himself doodling random formulas that none of his undergraduate students would have understood, but whenever he put down a plus or minus sign, she nodded at them.

The gunman had slowly cleared the bags from his partner using only his left hand, keeping the pistol steady on the hostages. When Charlie had first reached for one of the pads of paper that were strewn all over the floor, the gun had swung his way. His soft response, "Drawing paper for her," had apparently been innocent enough, and the gun had lowered.

Leeda had refused the pen, though. Without a word, she shook her head and buried her face in Charlie's neck again. With nothing else to do, Charlie started doodling.

The gunman watched him for a while and finally demanded to know what he was doing.

"Equations," Charlie answered.

The tall man loomed over the two of them where they sat on the floor and stared down at the paper, gun resting casually against Leeda's back and pointed at Charlie's shoulder. "Why?"

Charlie did his best to ignore the gun, but its proximity was making his stomach clench. "Some . . . um, some people pace," he explained. "Some people doodle pictures. I'm a, uh . . . I'm a mathematician, so I doodle equations."

The gunman stared hard at him, then spun and walked away. Charlie breathed a deep sigh of relief, and went back to his writing.

Solana and Benito sat next to each other on the opposite side of the aisle, their backs leaning against a register stall, his arm around her. Solana looked scared, but it was Benito that Charlie was beginning to worry about. Something about him didn't look right.

The gunman paced in between quick views out the windows and nudging his partner with his toe, who still hadn't moved. Everything seemed to be at a standstill, though Charlie knew there was a lot going on outside. The police would have called in the FBI because the savings and loan was federally insured, and they'd all be trying to gather information on the situation. How many hostages were there, had anyone been injured when the shots were fired, where were the hostages located in the building, how crazy were the robbers. All of the information would be distilled down into something that the agent in charge could turn into a plan.

He wondered if Don would be called to the scene. His brother was already on a hot case – one he figured he'd get called back in on soon, if he got out of this alive – so the odds weren't exactly in favor of him turning up. Especially if anyone figured out who was being held hostage. He didn't really believe the FBI would allow one of their agents to be in charge of rescuing his own brother. Just the same, if he could get word out somehow, maybe they'd bring him in as a consultant. It wasn't that Charlie didn't trust the other agents; rather that he trusted his brother more. And it wasn't because of their relationship, either. He'd seen Don in action, both working a problem and on a scene. Put simply, the genius in Charlie recognized expertise when he saw it, regardless of how much he knew about the actual subject, and Special Agent Don Eppes was an expert.

Charlie's mind began to wander, automatically figuring the probabilities of each of them surviving the next few hours. So many factors – it actually made a pretty interesting equation. He started fiddling with numbers, drawing graphs. A small part of him knew what he was doing, keeping his mind busy to keep it from dwelling on the harsh realities, but he shoved those thoughts aside and concentrated on the problem.

An equation . . . no, an expression . . . if Don _was_ out there . . . .

He started scribbling in earnest while the little girl watched carefully.

The gunman broke the silence. "You. Old man." He waved his pistol at Benito. "There's other doors, right?"

Benito nodded. "Yes, there's two doors in the back. The big one isn't open – I only open it up when there's a big truck – but the regular door isn't locked."

"Okay. You're gonna go back there and lock it. And while you're at it, you're gonna look outside and see where the police are, and you're gonna come back and tell me. And if you don't come back, I'm gonna shoot this pretty little gal you got your arm around."

"I . . . I . . . ." Benito gasped. His brown skin was taking on an unhealthy gray tinge.

"Papa?" Solana pulled away from her father and studied his face, her eyebrows creased together with worry. She turned to the gunman. "His heart – he needs his medicine."

"No – he's faking it. He's gotta check the back door before anyone does anything."

While the gunman's attention was on Benito and Solana, Charlie surreptitiously tore off the top piece of paper from the pad, folded it several times, and tucked it in his shirt pocket. Then he said, "He isn't faking it. He had a heart attack a few months ago. Just got back to work fulltime. Let me check the door, then get his medicine."

The man looked closer at Benito, then turned the gun on Charlie. "Okay. But leave the girl here. You run out the back and I'll kill her. You got that?"

"Yeah." He rose slowly, holding Leeda close, then limped over to Solana and started to untangle the little girl from his neck. "Go to Solana, honey. She'll give you a good hug, and I'll be back in just a minute to do more numbers. Okay?"

The little girl gradually gave up her death grip and allowed herself to be transferred.

"This won't take long," he reassured Solana, "and then I'll get your father's medicine for him, okay?"

Solana nodded, her arms surrounding Leeda. "It's a prescription bottle in his desk drawer, top right."

"Got it." He hobbled carefully around the gunman, acutely aware of the pistol that was pointed at his back all during the long trip to the rear of the store. He grabbed onto any merchandise or shelving on the way, trying to ease the screaming pain in his leg and finally reached the door, which was at the end of the aisle and in full view of the gunman. Hoping there weren't any trigger-happy cops outside, he opened it slowly and stuck his hand out first, then leaned out into the fresh air. It was another beautiful Southern California day. He wondered why he hadn't noticed before.

He counted two policemen out back – one to the right behind the dumpster, one to the left at the corner of the building. Charlie very carefully removed the paper from his pocket and dropped it on the ground. Then he waggled his hand in front of the deadbolt lock, hoping they'd get the idea, and without a word, backed into the store again and pulled the door shut. He flipped the deadbolt lock once loudly, then as he turned away, eased it off again quietly.

It was the best he could do. For now.

* * *


	8. Chapter 3, Part 2

**_The Unquantifiable Variable_**  
_By BeckyS  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Three, Part Two_**

Nolan was holding his earpiece close to his head when Don and Terry got back to him. He held his hand up, and they waited. A grin broke his face. "Someone just dropped something out the back door. I'm sending a man to pick it up."

"What kind of something?" Terry asked.

"My man said it looked like a folded up piece of paper. Maybe our first communication with the hostage-takers."

"What did the person look like that dropped it?" Don asked.

Nolan spoke into his mike. A few seconds of silence, then, "Wearing a white t-shirt with some kind of design on the front, with a button-down blue shirt hanging open over it, jeans, walking boots. One of the hostages, if they haven't switched clothes." He listened again. "Yeah, I think it's one of the hostages. The curly-headed man."

Terry looked at Don, and he knew she was judging his state of mind. She'd let him run with this as long as she could, but he knew she'd stop him cold if she thought his judgment was being affected.

"Is he okay? I mean, is he injured at all?"

Nolan lifted his mike again. After a moment, he replied, "Seemed in good shape, though he's got some blood on his forehead and a bloodstained rag around his left leg, just above the knee. My man said he was alert, looked like he had his wits about him."

Don blinked back the moisture that had suddenly gathered in his eyes. So if it was Charlie, he wasn't exactly unharmed, but he was okay. "Nolan," he started, "there's something I have to tell you." He was interrupted, though, by a young patrolman who ran up with something in his hand.

"Here it is, sir," he said, and gave it to the detective. "I think he left the door unlocked, too. It looked like he was checking out where we were, then he shot the deadbolt, but my partner thinks he drew it back again."

"I wonder if we can sneak in that way," mused Nolan.

Don considered it. "I don't think we'd better try a stealth entry from there. You can see that door from the front of the store if you're positioned right, and we don't know where they are in the building." He looked around. "Do we have a heat-seeker yet?"

"It's on the way," said Terry. "One of the teams at LAX just finished up with theirs, and they're sending it over."

"Equipment shortages," Nolan muttered. "I wouldn't think you guys would have to deal with them, too."

"Yeah," said Don. His hands were itching to take the paper from the detective. "So what does it say?"

Nolan unfolded it carefully and turned it. Then turned it again. He frowned. "This doesn't make sense."

"What is it?" Terry asked. She twisted her head around so she could see the page, too. Her eyebrows shot up.

He shook his head. "A bunch of math, I guess. Formulas. Equations. That much I get. I've got a nephew who's getting his bachelor's in this stuff. Looks like his homework. No note, though." He looked up, confusion plain on his face.

Don rubbed at his forehead. "Mind if I look at it?"

"Be my guest." He handed it to Don.

An older man in a dark suit with white air and an atmosphere of preternatural calm approached, and Terry distracted Nolan by introducing him to the Bureau's senior negotiator, Peter Jacobsen.

As soon as Don got a good look at the page, his heart dropped. Just what he'd been afraid of. Charlie's scribble. He handled it carefully, as much because it had just come from his brother as for purposes of maintaining any evidence such as fingerprints. "It's him," he whispered, and his hand dropped to his side, the paper brushing against his holster.

Jacobsen, who despite his age was built like a Navy Seal and had psychology degrees from two of the top universities in the nation, caught the change from his normal tone of voice. "Don. You know this guy?"

Don swallowed, but couldn't answer around the lump in his throat. He'd hoped, oh, he'd hoped he was wrong. "Yeah, Pete."

Terry took the paper from Don's hand and studied it. "You know we use math consultants sometimes."

Nolan nodded.

"We recognize the handwriting. Or whatever you call it. Even when it's equations, these guys have distinctive patterns to their writing."

"You think one of your consultants is inside?" Don could see Nolan running the implications. "He have any training in negotiation?"

"No," Don said. "No more than any genius can figure out on his own."

Jacobsen reached out to take the paper. He glanced at it, then looked again, harder. "Do you understand any of this?"

Terry laughed once. "Oh, no. No way. We're going to have to find someone to translate it for us." She turned to Don. "Didn't you say Amita—?"

Nolan broke in. "CalSci's right next door. They've got an incredible mathematician over there. Charles something-or-other. My nephew's in his class right now, in fact." He pulled out his cell phone. "I'll just call him—"

Don shook his head. "Don't bother."

Nolan kept dialing. "Look, I know you guys have your own experts, but from what my nephew says, this guy can figure out anything."

"Yeah, he could," Don sighed, "except he's the one who wrote the message. And it's Dr. Charles Eppes."

"My nephew's math teacher is your consultant?" Then the name sank in and Nolan's eyebrow slowly raised. "Eppes. As in . . . ?"

Don nodded. "My brother."

"Don . . ." Jacobsen warned.

The detective very deliberately put his phone away. "And you were going to tell me this . . . when?"

"Actually, that's what I started to say when I walked over here." He jammed his hands in his pockets. "Look, I know what both of you are thinking. In your position, I'd think the same. But setting aside the actual negotiations," he nodded at Jacobsen, "I'm the most experienced agent we've got right now to run this, and I've got something the rest of you don't. I know Charlie. Inside and out. I won't say I always understand him—" he nodded at the paper Terry still held "—but I've got the best chance of figuring out what he's going to do next. I'm not going to do anything to jeopardize this operation."

Jacobsen sighed. "I'll bet he's not one of those hostages who'll just sit there and wait for us to do our job?"

"I don't think so," said Terry. She waved the paper. "Witness this. He's already made a successful effort to get information to us. Don wasn't kidding when he called him a genius. Charlie is probably the most brilliant man I've ever met, and he's a master in a world that most of us can't even begin to comprehend. He appears extraordinarily intuitive, but most of the time that's simply because he's thinking so much faster than the rest of us, weighing and processing in seconds more data than we can hold in our heads. Every conclusion he comes to can be documented down to several decimal points."

"She's our profiler," Don inserted. "And she's worked with Charlie enough to have him pretty well figured out."

"It'll be a long time yet before anyone really figures out that brother of yours," Terry said, then turned back to Nolan and Jacobsen. "He thinks in a different way than what you'd expect. I'd call it thinking sideways, but when he explains it to you, you realize that it's very straightforward, very logical. Physically, though, he's not intimidating in any way. Has that sad-eyed puppy look."

Don jerked back and stared at her. "Puppy?"

She raised her eyebrows in apology. "He might be about to hit 30, but he still looks like an undergraduate." She paused and qualified, "A smart undergraduate."

"So the hostage-takers are unlikely to view him as a threat?" Jacobsen asked.

"Unless they try to outthink him," said Don. "He can get kind of obnoxious if he thinks you're ignoring his conclusions."

"My nephew says he's a great teacher," said Nolan. "His favorite professor."

Don nodded. "He'll spend hours with someone who's really interested, even if they don't know plus from minus."

Terry nodded. "I've watched him brief people who have a solid grounding in math. You should see the jaws drop when they get what he's talking about. Suddenly there isn't a word in three that you understand, but they're all nodding and grinning like they've just been given the key to the universe."

"Entertaining as hell, if you aren't trying to get them to figure something out on a deadline," said Don.

Terry scowled at him. "But what's more relevant to our situation," she continued, "is that he's also obsessively oriented to problem-solving."

Don rolled his eyes at the word "obsessive."

Nolan picked up on his reaction. "You mean he won't be able to resist working the situation."

"No way," said Don. "That's one reason you need me – to give us a chance to figure out what he might do." He dropped his gaze to the ground for a minute, then looked up them, decisions made. "Tell you what. I'll run the CP, coordinate the intel; Nolan, you and Pete here work directly together, and when and if the time comes, you take the number three slot on entry and clearing."

Terry shot him an approving look. Heck, he knew better than to lead a team into a situation where he might find his brother dead. For extra reassurance, he said, "Terry'll be with me all the way, and if she sees anything out of order, she'll kick me out."

"All right," said Nolan, "but I reserve the right to kick you out myself, if I see you doing anything stupid."

"Double-check is always good," Don agreed. "Now all we have to do is figure out what the heck Charlie's trying to tell us."

Terry nudged him. "Your dad's here."

"Oh, boy," Don swore.

"Amita's with him – I'll take the paper to her; you take your father."

"We don't need more family involved in this," said Nolan, his voice and body rigid. He glanced at the black-haired beauty who was walking next to an older man. "Who's this Amita? Your sister?"

"Amita Ramanujan. She's a post-doc at CalSci – Charlie's her thesis advisor," said Don. "She works with him all the time; probably has the best chance of anyone to translate this page. She actually understands all this stuff. Give me a sec to talk to my father – you'll brief Pete on anything else?"

"We'll need you in the CP in about two minutes," Nolan warned.

"I'll be there." Don angled to intercept his father. "Dad! Over here!"

Alan Eppes broke away and barreled up to his son. "Is Charlie all right? Where is he? I want to have a talk with that boy—"

Don put what he hoped would be a calming hand on his father's shoulder and gave it to him straight. "He's okay, Dad, but he's one of the hostages. A policeman saw him and said he's okay. He's already sent out a message – Terry's giving it to Amita to try to figure out."

Alan seemed to shrink, right in front of him. "You know that Charlie's not so good at this kind of thing. If it was you in there, I wouldn't be half so crazy with worry."

He took that as the compliment it was intended to be. "I know, Dad."

Amita walked over, gazing at the paper with the same abstracted expression on her face that was all too familiar to Charlie's family. She tapped it with a long fingernail. "He's upset, Mr. Eppes, he's working equations like mad, but he's also thinking clearly."

Don grimaced. "You mean he's back to working out insoluble math problems because he can't deal?"

"I don't think it's that bad," she answered. She gave him a glance of apology. "The figures aren't small and all crammed together like that time before your mother died, but he only doodles equations when he's either bored or trying not to be upset."

"Of course he's upset!" Alan threw his hands up in the air. "How could he be not upset? There's a man keeping him in that store at gunpoint!"

"Dad," Don warned, "I only have a minute. Amita, are you telling me he risked his life to drop a paper full of doodles?"

She shook her head and flattened the paper on the hood of a nearby car. "No, there's something else here. Most of these equations deal with probability."

He nodded – that was the job he'd wanted Charlie for later in the day. Now, if he could just get his brother out of this, he was thinking more along the lines of taking him out for a beer. After he gave him hell for scaring them all half to death.

"But see this one here," she said, "it doesn't fit. In fact, it makes no sense at all." She pointed to a single line that didn't look any worse to Don than the rest of the page:

±3 : 5βμM55(0)+ςμF21(+3)+M35(-2)+χεM29(+1)+λγF7(+3)  
2M26(+3)+ρικM23(-2)

"Why?" he asked. "What's different about it?"

"First thing, he's mixed Greek symbols from several disciplines. Along with straight mathematics and number theory, there are also symbols that are used for wavelength, electricity, photons, radiation, friction, electromagnetism . . . ." She shook her head. "Larry could tell you more, that all falls into his expertise, but I really don't think it's relevant to what's going on here. It's like this: If you were a German and reading an English newspaper, and all of a sudden you hit a paragraph written in pig Latin, it'd jump out at you, wouldn't it? And even if you weren't completely fluent in English, you'd know something was wrong with it."

Terry glared over her shoulder at the store, as if she could will Charlie to come out and explain himself. "It's that blatant?"

"To you and the robbers, no. To a mathematician, yes. It's set up almost like a legitimate expression, but it makes no mathematical sense at all."

"But Charlie doesn't do things for no reason," said Alan. "Sometimes we don't understand them, but the reasons are always there."

Don resettled his flak vest more comfortably. "I've seen him use equations to describe something. Is that what he's doing?"

Amita shook her head. "It's not an equation at all; it's nowhere near that cohesive. Whatever he's saying, he didn't use any mathematical system I've ever seen."

"We have to remember that he was doing it under the noses of the hostage-takers," said Terry. "If they thought he was writing a message, they never would have let him continue. Whatever information he's trying to get to us, he wanted it hidden."

Don rubbed at the back of his neck, trying to ease some of the tension from his shoulders. "Well, he succeeded. A little too well. Can you figure it out? I have to get to the Command Post, start trying to gather information on the hostage-takers and the hostages – who they are, how many, where they're being kept, what kind of shape they're in. I need to get a handle on what Nolan's men are doing, get things going."

"I'll work with them on it," said Terry. "You go ahead."

He nodded and caught them in his mind's eye for a moment; a snapshot in time. Amita, determined to translate this message from her mentor and friend; his father, perking up a bit at the thought there might be something even he could help with; and his partner, who would keep them on track and working quickly without them even realizing it. Satisfied, he jogged off to the Bureau's van.

* * *


	9. Chapter 4, Part 1

_I checked the stats this afternoon, and I'm overwhelmed at how many people are reading this story! Thank you! Some very nice comments, and more of them than I can respond to here without taking up entirely too much space. Thank you for writing, and for writing so thoughtfully. I'm glad to hear that so many of you feel that Charlie and Don are in character. _

_Alice, you brought up a question -- why did Charlie write in such a difficult code? Well, it's been my experience that when super-talented people get stressed, they revert to that which is most comfortable. Add that he felt he was under a severe time constraint, and he simply jotted whatever he could as quickly as he could. I'm sure he didn't think he was creating an unbreakable code -- in fact, I wouldn't be surprised if he had a moment of fear that it was too simple, and the gunman would see what he was doing, LOL! _

_A hint on the updates. They're coming fast, about 2 to 4 parts each day, so if you want to keep up, either login and mark that you want to be notified and then you'll get the correct URL in your email as soon as I post, or simply change the last number in the URL to the next, and see if anything is there. They'll go to about 18 total._

_And now we move on to Chapter 4, with just two parts . . . _

_

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_

_The Unquantifiable Variable_  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Four, Part One_**

Alan took the paper and ran his fingers lightly, lovingly, over the writing. He looked at Amita and shook his head. "I recognize some Greek letters, but then math is full of Greek letters. Charlie uses them like a second language. Actually," he smiled faintly, "like his first language."

"Maybe," said Terry slowly, "it _is_ a language. We know it's something he wanted to say that he didn't want to be obvious, but he also knew we'd have to translate it, so it probably isn't as hard as we're making it."

"A code?" Amita asked.

"Plus or minus three," Alan read from the paper, "and five divided by two."

Amita ran her finger under the top line and tried, not for the first time, to put herself in Charlie's head. "He's mixed Greek letters and English. Beta and mu, in lower case; mu in upper case; lower case sigma and mu again. Just an upper case mu in the third element. Then lower case chi and epsilon; capital mu; back to lower case for lambda and gamma. Two Greek letters for each element except the third. English "f" in upper case in the second and last elements."

"The bottom level," mused Terry, "doesn't have any Greek for the first part, but has three letters for the second."

"Amita," said Alan slowly, "what are those three letters?"

"Rho, iota and kappa."

"R, I, K in English?"

"Mm-hmm." She ran a hand through her long curls; flipped a strand back over one shoulder. "Charlie," she whispered, "what are you telling me?"

"Five groupings on top," muttered Terry, "have three capital "m's" and two capital "f's". The bottom has two "m's"." Her eyes grew wide. "Wait. Not 'mu' and 'f'; 'M' and 'F'. Male and female."

Alan deciphered it. "Two males below the line, three above with two females."

Terry nodded. "Two hostage-takers, both male; five hostages, three male, two female."

Amita pointed at the fourth part of the top line. "And this element here is Charlie. M29 – male, 29 years old, and Chi Epsilon – Charlie Eppes." She looked at Alan. "Beta Mu and Sigma Mu."

"Benito Mendez and Solana Mendez."

"Lambda Gamma."

He shook his head, but Terry said, "Leeda Gibson, seven years old." She turned her head to her mike. "Don, we've got something. Not all of it yet, but there are two hostage-takers and five hostages."

As Terry reported what they'd figured out so far, Alan continued to ponder the letters and numbers. "R, I, K. Rick?" he wondered.

Terry shrugged her shoulders and passed the possible name on as well. Then she went back to the paper. "But what are these numbers in parentheses?"

Amita frowned in concentration. "We know now that this is an expression created to describe people, so I'd say the numbers represent something about them that's measurable on a scale of plus three to minus three. Mr. Mendez is a zero, his daughter plus three and so on."

"Charlie's a plus one," said Alan. He grimaced in frustration. "What else would he want to tell us? What would he think would be the most important thing you'd need to know after how many people are involved?"

Terry turned to him. "How well do you know Mr. Mendez?" she asked. "This says he's 55 years old. Is he in good health?"

"Had a heart attack earlier this year. This kind of stress can't be good for him. Why? What are you thinking?"

Amita saw what she was after. "We need another data point."

Terry pointed to the M29 section. "Charlie's labeled himself plus one," she said. "The policeman who saw him said he looked like he'd been knocked around a bit, but was basically all right."

Amita took a deep breath. "Then the number associated with each person could be a measure of their condition or health. Mr. Mendez is ill but holding his own, the two girls are fine, there's an unidentified man in trouble but not dead—"

"Don," Terry called into her mike, "one of the hostage-takers, possible first name Rick, is down. Not dead, at least not when Charlie wrote this, but could be out of action. The little girl is fine, and so is Solana. Mr. Mendez is having problems, we'd better have paramedics ready to deal with a heart gone critical, and there's another male hostage who's in bad shape. That could have been the second gunshot. Charlie reports on himself just about what the policeman said – he's injured, but whatever it is, it's not major."

"That boy," muttered Alan. "That boy and his math. He always said it was a language. I never would've believed . . . Amita, can I have that? I'd like to keep it."

Though he didn't say it, everyone heard the 'just in case' in his voice.

"Terry?" Amita asked.

"I need to take it to the CP, show it to the negotiator. He hasn't worked with Charlie before; he needs to know how he thinks, and this will be a great way to show him. I'll hang on to it for you, though." She smiled. "This is going to help a lot for a lot of reasons. Going up against one hostage-taker is a lot better scenario than going up against two. Thanks to Charlie and to you, the negotiator will have a better chance to get Charlie and everyone else out safely." She took two strides in the direction Don had taken, then turned back for a moment. "Stay back here, okay? You'll be safe, and I'll know where to find you if I need you again, or if I get any more information for you."

They nodded, and she was gone.

"Mr. Eppes?"

"Yeah, Amita?"

"I know you can't predict the future, but . . . ."

His face was strained, but a smile twisted his mouth anyway. "Will it be all right? Will Charlie be okay?" He shook his head. "I don't know. I just don't know."

* * *


	10. Chapter 4, Part 2

**_

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_**

The Unquantifiable Variable  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Four, Part Two_**

Benito was leaning up against the checkout desk, eyes closed. It didn't look like the medicine had helped him much. The other customer was still lying facedown on the floor. The pool of blood under his right shoulder had slowly grown until the edges reached some of the pads of paper. Their edges were turning dark.

The gunman's partner hadn't moved or made a sound in over an hour. Leeda clung obsessively to Solana, who had scooted as close to her father as she could. Charlie sat on the floor amidst all the pens and pads of paper and scattered power tools. He'd adjusted the numbers for his entropy arc three times, each one showing a lower probability of the hostages surviving. He stared at the front door and tapped his fingers together as he turned over all the angles of the situation.

The phone had rung several times, but the gunman wouldn't let anyone answer it. Charlie figured it was whatever negotiator had been brought in. That was supposed to be the next step, to establish communications between the law and the people with the guns. He looked at his equations again, then the other hostages. If the FBI couldn't talk with the gunman, this stalemate could go on forever, and he was pretty sure that Benito and the two men lying on the floor didn't have much more time.

"Somebody's going to die soon." He saw Solana cringe from the corner of his eye. He looked up at their captor. "You, me . . . your friend, that man on the floor . . . . You can't keep us here forever. _You_ can't stay here forever." He jerked his head at the window, and the gunman followed his eyes and stared outside.

"You have to talk to them sometime. For your friend's sake it should be soon. For your sake, too." He waved at the unconscious hostage on the floor. "If he dies, they won't hesitate to shoot when you finally run. Right now, at this point in time, it was a mistake. Just a reaction. You didn't intend to come in here and kill people, but they're going to die anyway if you don't talk to the person on the phone."

The gunman tensed, and Charlie stopped. His years of teaching had shown him more about body language than the entire series of psychology classes he'd taken to get his credentials. It was part of what made him such an effective teacher, that he could read when his students had taken in all they were capable of, as well as when they had processed it and were ready for more.

The man moved back by his partner's side and knelt. He tried to feel for a pulse under the jaw, but since he had his gun in his right hand, he just fumbled around. He pointed the gun at Charlie, then waved it toward his partner. "You check," he said.

"I don't think I know any more about how to do it right than you do," he said, but he stood up anyway. His knee had stiffened abominably, and he looked around to see if there was anything he could use as a cane. He reached for a pole that had been holding small circular saw blades before it got knocked over, but was stopped by a hiss. He held his hands up in the air. "All right, but it's going to take longer that way."

He hitched his way awkwardly to the floor next to the young man and put his fingers where he thought the carotid artery should be. Nothing. He didn't want to think about what the gunman would do if his partner was dead. His hands were shaking, but he just pressed harder. Finally, he felt something. "There's a pulse," he reported, "but that's all I can say." He started to pull the mask off, then hesitated, waiting to see if the gunman would do anything. It was hard to tell expressions, but when he didn't threaten to shoot, Charlie kept going. When he had it off, he froze, stunned. "He's just a boy!"

"Just turned sixteen," said the other man.

Something about his voice grabbed Charlie's attention.

"My little brother."

"You dragged your sixteen-year-old brother into a bank robbery with you?" The appalled words were out before Charlie knew it. He bit down. He'd never change the probabilities in his favor if he antagonized the man.

"He wanted to come," was the defensive answer. "Wouldn't leave me alone about it. Wanted to help—" he heaved once for air "—his big brother."

Charlie nodded. "I know that one. Even when you know there's no way, you still want it with your whole being."

The gunman lifted his chin. "You got a brother?"

"Yeah. And I'm sure that right now he's worried sick about me and cussing me out at the same time."

He let loose a snort of laughter. "Yeah, you got a big brother, that's for sure."

Charlie rubbed at his forehead. It ached like the hangover he'd had the morning after he'd discovered Don's private stash in the garage. He'd been too young to be seriously punished – his mother had felt the hangover was punishment enough – but Don had been barred from every friend for two weeks, a terrible thing to do to a high school senior. He remembered how Don had waited until they were both of legal drinking age, then took him out every night for a week to teach him about all the different forms of alcohol and what effect they'd have. Charlie hadn't had more than the occasional beer ever since, but the memory of that wonderful week with his brother warmed his heart. His mouth twitched in a small grin. Maybe he'd take Don out to whatever his favorite bar was, after he got them out of this mess. "Your brother," he said. "I don't think he's going to make it if you don't get him to a doctor."

"I can't just turn him over to the police. They'll throw him in jail."

"I don't know about that. He's underage." He sat back against a wall of bags of peat and tried to relax. He didn't really want to ask, but he had to know because it would affect his calculations. "Have you shot anyone else?"

The gunman shook his head. "First time I fired this gun was those two shots in here."

Charlie sighed in relief, though he noted the phrase '_this_ gun.' "I don't know how the system works, but they'll probably get him well, then they might send him to a juvenile hall or something. Better that and alive than the alternative, huh?"

The gunman looked down at his brother, then out the window, and then turned his gaze on Charlie. "You tryin' to get out of here?"

Charlie laughed. "Sure I'd like to leave. I've already missed one class, I'm supposed to have another in," he checked his watch, "twenty minutes, and what I'd really like to do is get something cold on my knee and get stitched up, but none of that is going to happen, right?"

No answer.

He sighed. "No, I didn't think so." What next? Keep him talking and risk irritating him into some drastic action? If he could just convince the man to pick up the phone the next time it rang, the negotiator he knew the Bureau would have brought in might be able to make more progress. He wondered again if Don was out there, sure he must be by now, even if just as an observer. He doubted they'd let him run the show, not since they had to know by now that he was in here. The variables, they just kept shifting. His gaze was drawn to his notes.

"Look," he finally said. "We have three men here who are in bad shape and just getting worse. That makes your situation worse. You can't hold out here for whatever it is you want while they die, one by one. You don't need Benito and this other guy – they drag down the probability of your success by thirty two percent."

"Thirty two?" He swore. "How'd you figure that?"

"I'm a mathematician. I'm supposed to be able to do that kind of problem."

"Show me."

Charlie raised an eyebrow at him. "How much mathematics have you had?"

The man raised the gun.

"Ah. I see. That should be enough." He gave up on the idea of walking, and instead simply scooted back to his pile of notepads. He drew a long line from the middle left of the page so that it rose to near the top at the center, then dropped to a level below the starting point by the time it reached the right side of the page.

"This arch represents the tendency of all situations, whether in the physical world or in human behavior, to deteriorate into chaos. I could show you the equations for it, but trust me, it's about the right shape for this situation. This highest point up here at the top represents that moment of maximum deterioration." Then he drew a vertical line on the left edge that slashed from the top to the bottom of the page. "These lines," he drew more vertical lines to the right of the first at about one inch intervals, "represent the timeline. This point here," he tapped the meeting of the first vertical line with the arc, "is when you ran out of the bank. See how the line goes upward at such a steep slope to the second line? Am I right that things got out of control really fast, starting at that first point?"

No answer, but Charlie thought from his body language that he was still listening. He brought his attention back to the paper and pointed to a spot on the arc about two-thirds of the way to the top. "We're here, now, approaching the easing of the upward slope. Change is slowing down, but it's still happening. You can't get back into control, you can't stop the ascent to chaos, until you control the factors involved." He waved his pen at the two injured men. "And those are two factors you cannot control. No one in here has the knowledge or skill. If they die, the people out there are going to get really upset, and they won't care what happens to you." His finger slid along the line toward the top of the arc. "If you want to escape—" he paused for a moment, saw that he had the full attention of his audience, "—if you want to _live_, you have to get them out of here."

He sensed that he'd pushed as much as was wise, and so set the pad down on the floor, casually making sure it was visible.

The gunman backed away. He went to the registers and peered carefully and for just a moment out the front windows, then went back to kneel next to the other robber. Eyes flitting from Charlie to the body on the floor, he said softly, "Ricky?" When there was no answer, he slipped out of his jacket one sleeve at a time, switching his pistol as needed, and bundled the cloth under his brother's head. When he stood up, Charlie saw he was wearing a vest with webbed pockets on the front. It was much like the one Don wore into the field, except for one very big difference. The tops of what looked like hand grenades peeked out of two of the pockets.

He scrubbed at his face. His head ached with a sickening throb.

* * *


	11. Chapter 5, Part 1

_I'd like to add one note of appreciation and one caveat here. Appreciation goes to Suis and her husband who gave this story the once-over for law enforcement material. They both said that there was no way in heck that the FBI would have allowed Don to stay in charge . . . but that said, I wouldn't have a story if I took him out, so to go for it if I wanted. G> As Cheryl has said, sometimes you choose to ignore the facts in favor of the story. I've tried to give an at least marginally plausible reason, but for those who are sticklers, yes, I know. _

**

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**

**The Unquantifiable Variable**  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Five, part one_**

"Pete, any luck with the phone?" asked Don from outside the FBI van that was serving as the technological portion of the Command Post.

"No, not yet. For whatever reason, he doesn't want to talk with us." Pete Jacobsen took off his headset and scratched his skull where it had been resting. "I don't like it, Don. This noncontact usually means we don't have anything the hostage-taker wants. If that's the case, the chances of Charlie and everyone else in there making it out alive are pretty slim."

"It's early yet," Don offered.

"True, but this isn't a planned hostage-taking. These fellas were going to hit the savings and loan and run for it. They never counted on having to deal with hostages."

Detective Nolan rounded the corner, two cups of coffee in hand. He gave both to Don, who passed one in to Pete. "My men are just about finished checking the cars. There are only five we couldn't account for, and we've given the VINs and license plate numbers to your Agent Sinclair. He said he'd let you know what results he got from your database. I'm waiting to hear back from the DMV on the names and addresses for them."

"Good. If we could figure out who we're dealing with, we'd have a better idea how to go about it." Don rubbed his chin, thinking through the options that were coming clear and not liking any of them. If they couldn't talk the hostage-taker out, they'd have to do an enter-and-clear, and that was a good way to get innocent people hurt or killed. Like Charlie.

"Don?" Terry called. "One of our sharpshooters just called in – there's something going on in the front of the store."

Nolan and Don exchanged quick glances. Don dumped what was left of his coffee and ran to Terry's position. She had settled herself behind a Honda Civic that was about forty yards and a slight left angle from the entrance. There was just room for the two men to join her.

The sun was glinting off the plate glass of the store, making it difficult to see more than shadows. "I hope our shooter can see better than I can," Don said, and pulled out his portable telescope.

"He's the one in the back of that silver minivan." She pointed to a vehicle parked about thirty yards in a straight line from the entrance to the store. "No confirmation from our other man in the front, but his angle might not be as good."

Don could see where the pushout window of the van was opened just enough for the sharpshooter to do his job, but not enough that anyone inside the store would notice anything odd. "Our man in back?"

Nolan shook his head. "No action."

He pointed the telescope to the store entrance and studied the scene carefully. "One – no, make that two people moving around in the foyer. Looks like they're carrying or pulling something. One of them is a woman – must be Solana."

One of the double doors opened a crack, and a single hand appeared. Cautiously, an upraised arm clad in a blue button-down shirt showed, then Charlie limped out of the door. He looked straight at the car Don was hiding behind, and Don could clearly see the scraped bruise on his forehead, the blood-soaked jeans, and the stress in his eyes. He was holding both hands up. _Wait_, his lips said.

"Yellow light," Don commanded, allowing the sharpshooters to only take a shot if it appeared the hostage-taker was about to kill someone. "We need to see what's going on."

Charlie propped the door open, then went back inside.

"What is he doing?" swore Nolan softly.

"I think this is our first communication with the hostage-taker," said Don. "It's just not happening by phone."

Charlie reappeared, walking awkwardly backwards, carrying a burden that turned out to be a man who didn't fit the description of any of the hostages. Charlie angled his way through the doorway, and they saw that Solana had the man's feet. The pair carried him out and to the left as far as the last window, then set him down and went back to the door, Charlie limping painfully. After a moment, they came back out again, this time with a big blonde man who they set down beside the first man. Solana ran back inside, and just before going back in, Charlie turned to Don, his lips saying, _One more._

"Why aren't they running for it?" wondered Nolan.

"The hostage-taker probably threatened Solana with her father's life if she didn't come back in," said Terry. "If he threatened Leeda as well, there's no way Charlie would try to escape, not at the cost of her life."

Don could feel the energy building in the policeman at his side. He knew the feeling, knew the desire to do something, anything, now that there was some action. "Not yet," he said into his mike, but he knew Nolan heard it, too. "They're bringing out someone else."

This time it was just Charlie, with Benito leaning heavily against him. It took them what seemed a very long time to get to where the two injured men were lying, but they finally did and Charlie very carefully lowered Benito to the ground. He straightened, and his gaze swept the parking lot. Don knew the moment he spotted their father, for he started chewing on his lip. He looked back at Don, then hobbled back to the door. As he pulled it shut behind him, Don saw the anguish in his eyes, saw his lips move again, and then his brother disappeared back inside.

Don turned away from the scene and slowly lowered his telescope, feeling like he'd just been kicked in the gut. He couldn't let his emotions control him, though; not now. He reached down deep inside and pulled his professionalism around him like a cloak. "All right, everybody" he said, forcing his voice and manner into some semblance of his normal control, "let's regroup. Nolan, have your men pull those three out of there and get them to the paramedics. Terry, get Pete and David and go see if Benito can tell you anything – let's get some good intel for once. We'll meet at the CP in ten minutes and pool what we know."

"What are you going to do?" asked Nolan.

Don grimaced. "Go talk to my dad."

They split off to their tasks, and Don approached his Suburban at the back of the parking lot with heavy steps. He walked around to the far side, which was shaded by one of the few trees, and found Alan and Amita waiting for him. He ran a hand over his face. "You saw?"

"We saw," answered his father. Amita twisted her hands in her skirt.

"I saw you with your telescope, too," added Alan. "What did he say, anything?"

"Not really."

"Not really? What does that mean? He did or he didn't say something?"

"The first time he came out, he asked us to wait. After they brought out the first two men, he said there was one more." He stopped.

Alan searched his face. "And the third time?"

"Your eyes are better than you've been letting on," Don scowled.

Amita spoke for the first time. "He said he was sorry."

Don nodded.

"Sorry?" said Alan. "For what?"

"For getting in the middle of this," sighed Don. "For hurting you."

Alan rubbed at the back of his neck. "And let me take a wild guess – for putting you in the position of having to rescue your own brother."

"No," Don said slowly. "Not like that. He knows it's not like that." He looked up at the sky, trying to find the words to explain. Rescuing his brother. At one time it had seemed like a lifelong job, and he'd been honest enough with himself even back then to recognize the resentment. This was something different, though. "Dad, it's not Charlie's fault he got in the middle of this. He was just unlucky. It happens that way sometimes and he and I both know it, so there's no blame, no guilt left over from our childhood."

"Are you really so sure about that, son?"

Don nodded. "This is here and now, and this is what I do. Charlie's no more at fault than that little girl is. The blame sits square on the shoulders of the man in there with the gun."

Alan accepted his answer, but he wasn't finished. "If it's not your history with your brother that's tearing you apart, then what is it?"

He paced to the front of the car and gazed over the parking lot. The tools of his trade – the men and women, the vans, the threads of communications that connected them all, that held the operation together – everything was laid out in front of him. He turned back to his father. "The future," he finally blurted. "Dad, I have to do my job. I have to be objective, I can't afford to remember that my brother is inside, because if I do, I'll miss something and he could die. And I have to consider all the angles, consider the welfare of all the hostages – not just Charlie – and all the citizens I'm sworn to protect, and that means I also have to consider sacrificing him in order to get this guy."

"Don?" Amita gasped.

"I'm sorry," he said, "but we think there could be explosives. Look, there's an elementary school one block away for starters. I can't let that guy escape, no matter what the cost. And Charlie's words, his actions, they make me think we're right."

Alan took his shoulders in his hands and held him so he had to look straight in his eyes. "Tell me. Just what did Charlie say?"

But Don pulled away, leaned his forearm on the side of the car and dropped his head against his arm. "He told me . . ." He broke off, unable to say the words. He felt a warm, familiar hand on his shoulder and a gentle, woman's touch settle on his arm. He turned back to them, not caring if they saw the tears that clouded his vision. "He said, 'Do what you have to.'" He couldn't bear to add the final words he'd made out. _Tell Dad I love him._

* * *


	12. Chapter 5, Part 2

**_The Unquantifiable Variable_**  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Five, part two_**

Terry hid her professional evaluation well, but he knew she could see right through him. "I'm all right," he muttered in a gravelly voice as Jacobsen came up. "What've we got?"

Her raised eyebrow said she was reserving judgment, but she stuck to business. "Benito says that the two men are brothers. The younger one," she inclined her head toward the ambulance, "is sixteen, the older he's guessing is twenty-five or so. The man inside feels some remorse for getting his brother into this mess, but acknowledged Charlie's point that it was better to have him alive and in Juvenile Hall than dead on the floor of a hardware store."

"Charlie's point?" interjected Don.

"Yeah," said Pete. "Seems like he got a conversation going. Could be the hostage-taker isn't talking to us because he's talking to Charlie instead. His younger brother is injured, so he's talking to another younger brother."

Don raised a hand. "Wait a minute. Charlie is older than both of them."

"But he doesn't look it," said Terry, "and he knows how to act like a younger brother."

Don filed that one away to consider later – hopefully in a long conversation with said brother. "So what does the hostage-taker want?" asked Don.

She shook her head. "He never even mentioned demands. Benito thinks he's in over his head, that he was completely unprepared for this situation."

"Great," said Don. "We have a loose cannon on our hands that we can't even talk to."

Pete nodded slowly. "On the other hand, your brother isn't doing all that badly. He got two of the hostages out of there, along with the injured brother. That takes a lot of the time criticality out of the situation, gives everything a chance to settle down."

"He bought us some time," Nolan said, coming up behind them. "Do you think he'll keep working it?"

"Yeah," Don answered. "He's no quitter, especially when he's had some success. He'll keep at it."

"Which could be a problem," said Pete, a thoughtful crease in his forehead. "It could backfire."

"What?" said Don. "How?"

Terry nodded. "Say Charlie sets up a good relationship with this man on the basis of older-younger brother. He might be able to talk him out. But if the gunman finds out that you're out here, he could feel betrayed, and he could take that out on Charlie, or on us, trying to get at you."

"We need more information," Don growled. "We need to talk to him."

David joined the group. "We got an ID off a car parked by the bar that no one claimed; looks like it could be a match. Jason Mackey, age 25, and his brother Rick, 16. They live about five blocks north of here with their grandmother."

"That sounds like him," said Nolan.

David nodded. "I ran out and talked with her." He held out a picture of two young men, one in Army BDUs, the other in jeans and a t-shirt. The older had his arm around the shoulders of the younger, and both looked pleased and proud to be together. "Neither of the boys has been in trouble with the law before. Jason is ex-military, six-year hitch in the Army. Got out and came back home to discover his girl was two-timing him with a rich daddy from the Valley."

"Deployed?" Nolan asked.

"Yeah. He lost a jeep full of his buddies to an IED, took some shrapnel himself, and once he was mobile, the docs gave him a medical discharge."

Don shook his head. "Then he comes home expecting to be a hero to his girl, but the only one who looks up to him is his little brother."

Terry looked at the picture and took a deep breath. "And he thinks that maybe if he just had enough money, he can get her back. The military history gives more credibility to the teller's claim about explosives." She gave the photo back to David. "How much training do these guys get in disarming IEDs? Any? If he knows how to take apart an explosive device that someone else improvised, maybe he knows how to put one together, too."

They all just stared at each other.

"Okay," said Don, "David, find out."

He nodded.

"Before you go," Terry said, "any history of PTSD?"

"Not that the grandmother knew of, but she said he's changed."

"He would have, going through that," Don said. "We need his medical records."

"Already working it," said David. "Hey, I saw three of the hostages when I came back in. Good work."

"Two," said Pete, "plus the boy, Ricky. Wish I could take credit, but Jason still won't talk to us. Charlie somehow pulled that one off. Don . . . ."

"Yeah?"

"It's been long enough that Jason might be thirsty and hungry. We might be able to bargain another hostage out for food and water."

"All right, let's try again to get him on the phone. And David, see if you can track down that girlfriend. Maybe she can get through to him."

"On it."

Don grabbed him on the shoulder before he left. "Good work."

David's face lit up, and he headed off at full speed.

* * *


	13. Chapter 6, Part 1

**_The Unquantifiable Variable_**  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Six, part one_**

Charlie was once more sitting on the floor leaning against the checkout stand, his injured left leg stretched straight out in front of him, legal pad propped on his right knee. Solana leaned into his left shoulder, and Leeda sniffled softly in her lap. He'd continued doodling, working from memory on Don's internet vector problem. Even if he didn't survive the afternoon, maybe he could at least—

"Draw it again."

"The arc?" He was finding it more and more disconcerting not to be able to see the gunman's face.

"Yeah. Show me how it's different now."

Charlie tilted his head and cocked an eyebrow. "Would you take that mask off if I do? It's hard for me to tell if I'm explaining it right when I can't see your face."

"You don't want me to do that."

Charlie blinked. "I don't?"

He could see the gunman thinking it over, but in the end, the man shook his head.

"Nobody wants to see my face."

What caught Charlie's attention, though, was the way his eyes seemed to linger on Leeda just before he refused. He tried again. All of his instincts were telling him to make a connection with this man, and it was hard when he couldn't read his face. "I teach better when I can see my students."

"Teach?" the man asked. "I thought you were a college kid."

"Not since I was twenty," Charlie answered, and his eyes dropped to the equations on the papers on his knee. He had long accepted that he was different, but this kind of conversation always made him uncomfortable.

"You quit?"

In spite of the situation, he laughed at the thought that someone would take him for a college dropout. "No, I finished my Ph.D."

A small sound from his side drew him to Solana. His heart dropped. There it was, that look that said so clearly _you're different_ and then changed to _I don't know you – I can never know you._ He sighed.

The gunman cocked his head. "Your brother didn't mind?"

Now Charlie really did smile. "Oh, Don minded, all right. He minded a lot. He was pretty good at hiding it, though. He'd do other things, stuff I could never do, like play baseball and get girls and hang out with the cool guys. He let me tag along sometimes. I wanted so much to be like him. There were times I would have given up every IQ point, just to be like him." He shook his head. "I don't think he ever knew, back then. Now . . . maybe he knows now. I hope he does." He looked down at the graph and fidgeted with his pencil, darkening one of the characters, the triangle that appeared at the bottom of each marked off section.

"I didn't believe him," muttered the gunman.

"Who?" Charlie asked.

"My brother." In one quick motion, he pulled off the mask.

Solana gasped and tucked Leeda against her breast, keeping her head turned away. Charlie felt his stomach lurch. The right side of the man's face was a mess. Angry red scars twisted the corner of his mouth up in a parody of a grin and dragged his eye down in a cast that made his face look like evil incarnate. Tissue was shiny where there was textured beard on the other side of his face, and skin was stretched into odd wrinkles where it should have been smooth.

"What . . . ." Charlie swallowed bile, "what happened?"

"IED," he said simply. "Iraq."

"Can't the doctors—?"

"Not soon enough." His whole attitude was matter-of-fact, as if he'd come to understand what his life would be like from now on, as if he believed it would never change. "VA's swamped, said the docs have done as much as they can for now." He glanced at the front doors. "My brother said it didn't matter, that it didn't change anything. That we were still brothers. It did change things, though."

Charlie wondered how he'd feel if Don had been injured so horribly. Could he take it as well as Ricky had? Could he look Don in the eye and tell him it didn't matter, it made no difference? He nodded slowly. If it meant his brother was alive, instead of gone like his mother—

Oh, God, he had to get out of this. He couldn't let his family lose someone else.

Leeda screamed. Her voice went right through Charlie, drilled straight to the ache in the back of his head. She was staring wide-eyed at the gunman, and it seemed she'd never stop. Solana tried to calm her, but Leeda saw nothing but the maimed face in front of her, and breath after breath just kept the screaming going.

The gunman raised his pistol and looked around frantically. "Stop it!" he yelled. "Shut up!"

"It won't work," Charlie yelled above the noise. "You have to let them go. The police are going to hear her and bust down the door any minute, and they're going to shoot first."

Solana sobbed while she tried to hush Leeda. "Please," she asked. "Please let me take her."

The red marks on the gunman's face stood out lividly.

Charlie rose carefully to one knee, aware that the robber was on a thin edge. "You don't need them," he said. "You have me – you don't need them."

"I can't – I have to – No! I need leverage!"

The phone started to ring, and in the cacophony, Charlie saw the gunman's hand start to shake.

Charlie used the checkout stand to pull himself up the rest of the way and then put himself in front of the girls. He had to keep the man's attention. "You have leverage in me. The FBI is out there and they know I'm in here. They know me – I work with them sometimes – I'm working on a case for them right now." He gestured at all the equations on the papers. "That's what all of this is. They're tracking down a mob killer, and they need me to help them. They'll do anything you want to get me back safe because I'm the only one who can analyze their data. Talk to them, and you'll see." It was a blatant lie – they would do a lot, but not anything – and he knew it even if the gunman didn't. Don couldn't risk letting this lunatic back out on the street. Maybe the man wanted the money to pay for plastic surgery, he didn't know, but he could read determination when he saw it. He made his voice calm, forceful. "You don't need them. Let them go. They're driving you toward chaos, toward the apex of the arc. You have me – it's enough."

The gunman shook his head and fingered his vest. "No – a little girl – they care about a little girl."

"They care about me more," he said.

The phone kept ringing.

"No – I don't believe you."

Charlie knew he had to play his last card. He took a step forward and waved at Solana behind his back. He kept himself in between, kept his eyes on the man. "You remember I said my brother is probably out there." The sudden change of subject caught the man's attention. Charlie could hear Leeda's cries coming from a little farther away. He kept staring at the man's eyes, forced himself to ignore the horrific injuries that surrounded them. "Well, he is." He took a deep breath. "And he's in charge."

"What?"

"He's a Special Agent with the FBI."

"I don't believe you."

"Pick up the phone and tell them you'll only talk to the Agent In Charge. When he gets on, ask him his name." He reached carefully into his back pocket and pulled out his wallet. He drew his university ID from it, the one with the silly grin and the curl that had fallen over one eye from laughing at something the picture technician had said. He held it out. It was recognizably his face, and in bold letters it labeled him Charles E. Eppes, Professor. "The Agent In Charge will tell you his name is Don Eppes. He's thirty-six years old, and he's my big brother. We just lost our mother a year ago – he won't let anything happen to me. It would kill our father." He waited. The man needed time to process it all, and it was hard for any of them to think with Leeda still shrieking. "You don't need them. I'm leverage enough."

The gunman shifted his pistol to point at Solana. "Pick up the phone," he ordered.

* * *


	14. Chapter 6, Part 2

_AN: I have the greatest respect for the members of the U.S. military, as well as for the overworked personnel of the military and Veteran's Administration hospitals. I know and work with many, andthis story is in no way, shape or form meant to be a criticism of them or their organizations._

**_

* * *

_**

The Unquantifiable Variable  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

_**Chapter Six, part two**_

Terry was headed back to the Command Post van from a check with the sharpshooters when the high-pitched scream of a little girl pierced the air. "What—?" Her body whirled to face the store and she whipped out her gun.

"That's Leeda!" cried Mrs. Gibson. "That's Leeda – do something! They're hurting my baby!"

The policemen all began to surge forward, but David and Terry moved in front of them. "Not yet," Terry said. "Give us just a second to find out what's going on." She spoke into her shoulder mike. "Someone give me some intel," she demanded.

"Shooter One," came a voice she recognized as the man in the back of the van. "There's movement inside, but no shots fired."

"Shooter Two. No action in back."

"Shooter Three – I see two people facing each other, bodies rigid. Might be facing each other down. Can't tell who's who. No sure shot at this time, it would be through two panes of glass."

"Shooter Three, Shooter One. Give the word and I'll take out the first window from here."

"Control?" asked Shooter Three.

"Keep it ready," Don's voice said over the mike. "Terry, get in here, someone just picked up the phone inside.

Terry picked Nolan out of the group. "Pete's made contact."

"Stay on alert," Nolan ordered his men, "but do what the Feds say." He stuffed his weapon in its shoulder holster and followed her.

Terry climbed up into the van to discover Pete handing the headset over to Don. "What's going on?" she asked.

Pete shifted out of the way. "It's the woman inside – Solana. She said the hostage-taker will only talk to the Agent In Charge."

A burning started in Terry's gut.

"Yeah," said Don into the receiver. "That's me."

There was a pause, and Don's expression changed ever so slightly to something between confusion and wariness. "Don Eppes," he said, then, "thirty-six."

"He's got the hostage-taker," she whispered to Pete.

There was a longer pause, and then, with great reluctance, Don said, "A year ago. We lost her a year ago."

Nolan tried to push through. "What's he doing on the phone? I thought we agreed he'd stay out of this."

"I don't think he can." Terry knew her partner well enough to fill in what the hostage-taker was asking. "I think Charlie told Jason about Don."

"What!" Nolan backed against an equipment locker in shock. "That's crazy."

"He must have had a good reason, but I have to agree with you. Regardless, it's the situation we have to deal with now."

"Terry!" It was David, yelling from outside the van. "The woman's coming out, and she has the little girl."

She touched Don's arm. "Charlie's the only one left in there."

Don nodded, eyes creased with worry.

"I'm going to go talk with Solana," she said, "see what I can find out."

He nodded again, but kept most of his attention on the phone.

She ran across the parking lot, gun in hand, hair flying, and took Solana from the policemen who were escorting her. Leeda was still whimpering, but as soon as she saw her grandmother, she started crying again.

"Solana," said Terry. "Tell me what happened – why is Leeda crying? Did he hurt you?"

"No," she said, but her eyes were haunted. "His . . . his face . . . it was such a shock. He's hurt so bad."

"Hurt how?" She took Solana by the arms.

"Iraq, he said. We were all so scared of him, so afraid he'd hurt us – that he'd kill us. I . . . I don't know what to think. How could someone live like that? How can he stand to look in the mirror?" She was shaking under Terry's hands.

"Is Charlie okay?"

Solana looked up. "You know Charlie? Oh, yeah – he's the brother of one of you guys, isn't he? He's . . . well, there's something wrong with his knee. He's scared, like all of us. But he's talking to the guy."

"Solana, what did Charlie tell Jason?"

"Who?" she asked in confusion.

"Jason – the hostage taker. His name is Jason."

She shook her head. "I didn't know. He never said. He didn't even take his mask off until . . . ."

Terry took a guess. "Just now? Was that why Leeda started screaming?"

"Yes. She was terrified."

"This is important. Tell me what happened."

Solana repeated the conversation the best she could remember, but Terry could see she was still completely unnerved by the whole experience.

"All right," she said finally. "I want you to go with Agent Sinclair, here. David, take care of whatever she needs, but keep her near in case Don has questions."

"It's all right now," David told the girl. "Come on back here, and we'll get you something to drink." He led her off, murmuring comforting words of reassurance.

Terry climbed back up into the van to see Don with the headset in his hands, deep in discussion with Pete.

First thing she knew he wanted to hear, "Charlie's still okay. Solana says he's been showing Jason some equations, and then talked him into believing that he didn't need her or Leeda. Charlie kept telling him that he was enough leverage, that you'd do whatever he wanted because your Dad couldn't handle losing another member of your family."

Don rubbed his face. "Charlie knows that I can't do that."

She nodded. "Yes, he does. But that wouldn't stop him from trying to convince Jason of it, if he thought the girls were in danger. And from Solana's description, I'd say Charlie pulled him back from the abyss just in time."

He stood. "I need some fresh air. Pete, make sure someone calls me if Jason gets back on the phone, but if we can do it, I want you to talk to him. Put him off, make him wait, give him time to calm down. You know the routine."

Jacobsen didn't take offense at being told how to do his job. He merely said, "All of us, Don, we'll get your brother out."

Don didn't take that as a guarantee of success, they were all too realistic for that, but as a promise that everyone was running flat-out to find a solution that would save Charlie. "Thanks," he said, his voice strangled.

He and Terry left the van and moved a little ways from it. A young but very competent looking policewoman with flaming red hair tucked neatly under her hat approached, two cardboard cups in hand. "Agent Eppes? Agent Lake?" she asked. "Thought you could use something hot."

He reached for it, popped the lid off, blew once across the top, and took a hefty sip. He glanced at her nameplate. "Thanks, Officer MacDill. How's the girl?"

The policewoman jerked her head to the right, and Don followed her gesture. Leeda was wrapped around her grandmother, thumb in her mouth, blanket covering them both. "Physically, she's fine. She'll likely have nightmares, but we'll set her and the family up with a counselor."

"Good. Any word on the brother and the other hostage?"

She pressed her lips together. "The other hostage has a good chance; he's in surgery now. Ricky—" She shook her head. "It doesn't look good. He's got a pretty severe head injury. If you were thinking about using him to talk his brother out, it's not going to happen."

Terry ran her hand through her hair. "If Jason's brother dies, he's going to have even less reason to live, or to keep Charlie alive."

"Keep that under your hat," he told MacDill. "Make sure the media _does not_ find out. We have to control what Jason learns, and we don't know if he's got a radio in there."

"Solana didn't mention anything like that," Terry said, "but I'll check with her again."

"Don!" Jacobsen called. "It's Charlie!"

He leaped for the van and nearly tore the headset from the negotiator's hands. "Charlie?" he gasped.

"Don, I'm all right."

He didn't sound all right; his voice was strained and cracking. Don fought back his emotions and tried to keep professional, though he let a hint of warmth into his voice. "Hey, buddy, we're going to get you out of this."

"Maybe. I hope so. I . . . I don't know. He's—"

Faint voices, then Charlie was back. "He wants a car." He disappeared again, and Don faintly heard, _won't work . . . don't have a driver's license._

Don knew Charlie could drive, had had a license in the past, but as distracted as he got under the best circumstances, Don hated to think what would happen if he got behind the wheel with a gun at his head. They wouldn't have to chase the car; it'd probably run off the road on the first turn. He would've let him do it, too, if there'd been some kind of guarantee that the gun wouldn't go off at the same time.

"Charlie!" he called into the mike. "Charlie – listen!"

"He's insisting on the car, Don."

"Put him off. Keep up with the thing about not driving. Tell him you'd wreck it in the first mile. Whatever it takes. Tell him we need to work out what we're going to do about it. He needs to talk to us and tell us just what kind of car he wants – two-door, four-door, pickup, sedan – we need all those details. And ask him if he's hungry. Tell him we offered to send in some food in the meantime. Charlie, we have to slow him down, calm him down. Getting him to focus on the details will help get his head back into real life."

"Okay."

Don could hear a deep breath.

"I'll tell him. I don't know if . . . he might not listen, but I . . . I'll try."

There was silence again, but Charlie hadn't hung up. Don found himself tapping his fingers on his leg in his impatience. He couldn't make out the words, but he could make out Charlie's voice, and there was an underlying despair to the tone that he didn't like.

Finally he came back on the line. "He doesn't know about the car. He'll think about it and get back to you."

"That's great – give us another reason to talk to him. And the food?"

"Pizza. There's drinks here in a cooler. Pepperoni."

"Okay. Good job, buddy. Pepperoni pizza." He saw David pull out his cell phone. "We'll get it as soon as we can, but it'll be at least 45 minutes, maybe an hour. Tell him that."

"Yeah." It was his distracted voice.

"Charlie – did you get that?"

"Forty-five minutes. Yeah." Then, in a voice that belonged to a bewildered child, he said, "He's hurting, Don. He's hurting bad, and he doesn't believe it will ever get better."

_Damn!_ "We can get him some painkillers if you need them."

Charlie laughed once, a harsh, brittle sound that struck Don in the heart. "Oh, we need them, all right, but they can't fix . . . not this."

"What – what can't we fix, Charlie? Tell me, and I'll find a way."

"I have to go. Tell Dad—"

"You tell Dad, okay? You hear me, Charlie? You're gonna tell Dad at dinner tonight whatever you want him to know."

"Don, don't. The probabilities – I see them – they're as clear to me as this phone in my hand. They're . . . well, they're not in a realm that promises any kind of success. You'd have a better chance to call a coin toss right ten times in a row."

"But there's a chance, right? There's a chance, no matter how you cut it, right?" Charlie didn't answer, and he started to get mad. "Don't you give up on me. Not now, not when you've done so much already."

"Don . . ." his voice cracked, and Don barely heard his "goodbye."

"Charlie!"

But he was gone.


	15. Chapter 7, Part 1

****

The Unquantifiable Variable  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Seven, Part one_**

Don walked around to the back of his Suburban where his father and Amita waited. They both started to rise, Amita from the curb, Alan from the floor of the car where he'd been sitting. The raised chassis made it about campstool height, much more comfortable than the ground.

"Charlie's still okay," were the first words out of his mouth, and his father sank back.

"We heard the screaming."

"The little girl. Jason – that's the hostage-taker – has a damaged face. He kept his mask on until just a little while ago. I guess it's pretty bad."

"What are you doing now?" Amita asked.

"We got a little breather. Jason wants a car, but Charlie told him he can't drive it. We told him it would take time to work it out, and we're sending for a pizza in the meantime."

"Pizza?" said Alan, outraged. "How can you think about pizza when your brother's life is in danger?"

Don waved his hand at his father. "Not for us, Dad; for them. It keeps him waiting for something – sets up some time with no pressure. We get a chance to reason with him when he's not all hyped up."

Alan scrubbed at his face. "If I weren't already going gray from all the hijinks you two have pulled, this would do it." He looked up. "How is he? Really?"

Don shook his head. "Physically, I think he's probably okay."

Amita moved closer to his father. "But mentally?"

Don chewed his lip, wondering how much to tell them.

"Donnie . . ."

"He's scared, Dad, that goes without saying, and with reason. Jason isn't exactly balanced – he's had some bad stuff happen to him, and he's gone over the edge. Charlie's managed to build some kind of rapport with him, and that should help protect him, but with someone like this, there could be hidden triggers, things that would set him off that we just don't know about. We're keeping the situation as stable as we can, but Charlie – well, he's at his numbers, and they aren't making him feel any better."

"Did he tell you?" Amita asked.

"Not really. Something about no better than calling ten coin tosses right." He regretted saying it as soon as it was out of his mouth, because she paled and had to steady herself against the side of the car. Fortunately, his dad didn't notice.

Alan rubbed at his forehead. "Not good, but then Charlie probably didn't figure in one very important factor." He looked up at his son. "You."

π π π

The deadline for the pizza was closing in on them. The delivery man had actually arrived, but had parked out of sight of the front of the store and was now taking off his jacket and hat to pass them to an agent. As requested, the pizza had not been cut, and the box had a plastic bag inside with plates, napkins, and a plastic knife. Most hostage-takers wouldn't let their hostages anywhere near a knife, even a plastic one, so that meant that Jason would have to cut the pizza and share it with Charlie. One more step in the web of dependency the Eppes brothers were building; Charlie instinctively, Don by design.

Terry had volunteered to drive the car for Jason as she was the least physically threatening agent they had. Don knew her appearance was deceptive – she was strong, quick and wily – but it worked in their favor. Jacobsen had called the hardware store and Jason had answered, and they'd gotten into a long, involved discussion about cars and their relative worth. At the end of the call, Jacobsen told Jason that someone had reported that the pizza was on its way, and he'd work on getting the right car while he and Charlie got something to eat.

They all gathered at the back of the Command Post van.

Jacobsen finished his report on the conversation. "He's agreed to let the delivery man set the pizza just inside the door. From his state of mind, we'd better use someone who doesn't look too intimidating."

"I can't do it if I'm going to drive," said Terry. "He'd know we were up to something if he saw me do both."

"I want you with the car," said Don. "You know Charlie so you'll be able to pick up any subliminal messages he's sending off, and you can handle whatever comes down."

He looked at his team, which now included Nolan. They were all looking to him for direction, everyone seeming to have forgotten their reservations about having the brother of a hostage in charge. "The most likely time for everything to go to hell is when Jason comes out to get in the car. Terry, you're going to have to time it close. Stop by the parking spaces, not by the store. You can't let him actually get in; it just has to look like it. Tell the shooters that I want to keep this guy alive if we can, but Charlie is not expendable—" he glanced at the police detective, "—and not just because he's my brother. This situation does not warrant saving the hostage-taker at the expense of a hostage's life. Just the same, he's not so much a criminal as just someone who's been screwed pretty bad by life. If we can get him through this and get him some help, he might be okay in the long run. I want to brief the shooters personally – David, can I get just them on a channel?"

"I'll set it up."

Nolan nodded. "It all sounds good. I'll brief my men as soon as we finish here. So, next question, who delivers the pizza?"

Don ran the personnel at hand through his mind. "That young policewoman. She seems to have her head screwed on straight."

"Yeah. MacDill. She's not as young and inexperienced as she looks – just got out of four years in our youth undercover program."

"Even better," said Terry. "If you'll ask her if she'll volunteer, I'll brief her on what we want her to do. She'll be the only pro who'll get a chance to see the layout up close. You'll need to know as much as you can if you have to do an entry-and-clear."

"Okay," said Don. "We call Jason, tell him the pizza's coming in. Your MacDill gets what intel she can without compromising her cover, and we meet back here. Then we take what she's got and build an entry-and-clear plan as a backup. We need to relieve Shooter Three in the back so he can be in on it. If something blows up during the pizza drop, Shooters One and Two take out Jason. All clear?"

Everyone nodded.

"Let's go."

* * *


	16. Chapter 7, Part 2

**_The Unquantifiable Variable_**  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Seven, Part two_**

Officer Brenda MacDill was thrilled with her assignment. She loved being undercover anyway, and the chance to do something directly to resolve this situation drove her to volunteer almost before Nolan had the words out of his mouth. She was also honest enough with herself to know that the chance to show her stuff in front of a group of FBI Special Agents was driving her, too. She was particularly impressed by Agent Eppes. She could see the pain lurking in the backs of his eyes, but he hadn't slipped once. He was a professional all the way. She also liked Terry Lake. Both of the women were petite, tiny in a world that valued strength, but Agent Lake had an inner toughness that Brenda recognized. She hoped she could get to talk with both Eppes and Lake after this was all over – she had a feeling she could learn a lot from them.

In the meantime, she had a job to do. She and Terry had moved to the agent's car where Brenda could leave her patrolman's clothes. She slid out of her blue uniform shirt first, to reveal a tight white tee and a strong physique beneath. She tossed the shirt on the back seat of Terry's car, then took off her equipment belt and handed all but the gun to Terry. The gun went under the waistband of her pants at the small of her back. She took her hair down from its tight pins and tied it into a high ponytail with a handy piece of string. Terry handed her the pizza man's ballcap, adjusted more to her size, and she pulled the ponytail through the back of it. The jacket was too big, but she simply rolled the sleeves up and fastened the bottom of it, not so coincidentally hiding the gun and the tailoring of her pants. She scuffed a little dirt over her spitshined shoes and hoped the hostage-taker wouldn't look too closely.

"Got a lipstick?" she asked.

"Hang on." Terry reached into her car's glove compartment and drew out a small cosmetic bag.

Brenda used her finger to swipe some color from the side of the lipstick and rubbed it on her lips, then used a second swipe to apply to her cheekbones for blush. She shrugged. "Anything in a pinch."

Terry grinned as the patrolwoman relaxed from her previous almost military posture. The transformation from competent patrolman to high school senior on an afterschool job had taken all of four minutes. She'd already passed on the information they needed, but felt compelled to add just a little more. "Officer MacDill, we don't know who will come out to get the pizza, but if it's Charlie, remember that although he's a very, very smart man and he's helped out with some of our cases, he's never found himself in a situation like this before. Don would kill me for telling you this, but he said it sounds like Charlie's giving up hope. If you get a chance to say anything to him, remind him that we aren't giving up, that we honestly believe we can resolve this peacefully."

"All right, I'll see what I can do if he comes out." She tilted her head in question. "This Charlie, he means a lot to you, too."

"Yeah, he's pretty special. Not just because he's Don's brother or because he's a certified genius, but just because he's . . . well . . . Charlie." She stopped in frustration. "I'm supposed to be able to do better than that."

Brenda placed a hand on her arm. "That's okay. There's a few people in this world who simply defy description. Sounds like he's one of them."

"Hopefully you'll get to judge for yourself, later."

She grinned. "I'd like that. I'd like that very much. But right now," she settled the jacket more comfortably on her shoulders, "I have a pizza to deliver."

With a quick nod in the direction of Detective Nolan, she headed for the pizza car. The real delivery driver handed her his keys with a worried smile. "I'll take care of your baby," she pledged. He stepped back, not particularly reassured, and she drove off the lot and back out into the street. She came back into the lot from the entrance closest to the left side of the hardware store. This meant she'd have to cross the rest of the access lane to get to the door, but it also left the sharpshooters and the Command Post more room to see what was going on.

She stopped short of the entrance, even with pallets of bags of grass seed that were settled on the wide sidewalk. She climbed out of the car, retrieved the pizza box, and with a deep breath, angled to the right to the door. Someone was moving around inside, but she couldn't tell yet who it was. She'd seen Charlie Eppes help bring the injured people out of the store, so she knew what he looked like, but when the front doors of the store slid open and revealed him, she felt a slight shock anyway. Bruised, worn and battered he might be, but he had the most beautiful eyes she'd ever seen. _Puppy-dog eyes_, she thought, not realizing she was echoing another woman. _Especially now._ Deep brown, almost black, they held the same pain that she'd seen in his brother's eyes. But Charlie's also showed almost unbearable weariness. He was stretched to the breaking point, all right.

He reached for the pizza, and muttered, "He has a gun on us from the left."

Her eyes shot in that direction, took in the chaotic mess on the floor directly behind them, and then steadied themselves on him. "Believe in your brother. He'll get you out."

Something flickered in his eyes, lit them with a warm glow from within. They had only seconds, but he replied, "I will," and a small grin lifted one corner of his mouth.

Then he turned away, and she ran back to the car. She threw it into gear and sped off, just as a panicked delivery-person would. When she got back to the real pizza man, she eased to a stop and got out. As she shed the jacket and hat, her mind was spinning with details that were already working into a cohesive report, but overriding it all was the conviction that she simply couldn't bear it if that light was extinguished forever.

π π π

Another down time. Time to regroup, time to analyze, time to plan.

Don rubbed at his increasingly gritty eyes and wished for a slice of that pizza and even ten minutes of sleep. Things were coming to a head, though. He could feel it. In no more than an hour, he'd either have Charlie out of there and on his way home, or—

No. He couldn't think that way. He had to take it one step at a time.

π π π

One slice of pizza. One bite of one slice of pizza. It was all his stomach could handle, even with the encouraging message from the girl. _Who is she?_ he wondered. He'd never seen her around Don's office, so maybe she was LAPD. _Awfully young._ Then he laughed at himself. Who was he to judge how young a person could be and be competent.

The gunman – he wished he knew the man's name – had pulled a couple of soft drinks from the cooler and handed one to Charlie. He downed it in about ten seconds, astonished at how thirsty he was. Then he sat back down on the floor and picked up his pad of paper. The chart stared up at him and his eyes were drawn to the little triangles, the first one darker than all the rest. He outlined all of them, giving each darker, bolder lines. _Delta_. Change. Incremental change, caused by a variable. The variable that could change the balance of the entire equation.

π π π

Alan Eppes paced from one end of the Suburban to the other. Amita had shifted to his spot on the floor of the SUV and watched him with worried eyes. Neither interfered with the other, neither offered useless platitudes, but their thoughts were remarkably similar. _Keep him safe. Bring him back to us. Let him live._

π π π

Terry went over the car that had been delivered. A new Honda Accord was what Jason had asked for, a note of wistfulness in his voice. Sapphire blue with gray interior. Terry made sure she knew how the door locks and automatic windows operated from the keypad at her left hand, and set the seat and adjustable steering wheel at comfortable angles. She'd drive up to the same spot Officer MacDill had used. It would make Jason travel farther from the door to get to her, and every step he had to take was that much more time they had to get him to give up.

π π π

Detective Nolan stood near the Command Post, flanked by three FBI agents and Officer MacDill, each checking their equipment. Brenda was back in uniform, though the borrowed flak jacket covered her from neck to legs.

Based on the tipped over display walls and merchandise that littered the floor, Nolan and Don had decided the entry-and-clear team should position themselves at the back of the store. They'd take over if Jason retreated back into the store. They'd practiced together, learning each other's signals as quickly as they could. It was unusual to mix a team like this, but then this was an unusual situation. Each member of the team, though, was completely dedicated to making it work, and that would be the difference.

David Sinclair would be on point with his pistol in hand, the first to enter, the first to engage the hostage-taker, if needed. The second man was also FBI, a big man in whose arms the submachine gun looked like a toy. They'd worked together enough that they would automatically avoid creating a crossfire situation. Nolan would be third, the team leader, who would be far enough back to make quick decisions or changes in tactics. Fourth was Officer MacDill in the other clearing position, armed with a shotgun in case the hostage-taker got behind any locked doors. The final man from the LAPD was probably overkill, but he carried a small battering ram which might be needed. Each member of the team checked their weapons one last time, strapped on their black helmets, and then carefully filed to the back of the hardware store.

π π π

As if telepathy existed among the law enforcement personnel, a single thought seemed to float through the air: _It's time._

* * *


	17. Chapter 8

_Apologies for the delay -- I had planned to have this up Saturday morning, but we ran into a glitch at work and I've hardly even been home. Anyway, here's the end of the story. If you're one of those folks (like me) who likes to print stories off, you might want to wait a week or so -- I have a couple of minor things to fix up which I'll take care of in the next few days. Thanks for coming along for the ride. I hope you've had as good a time reading this as I had writing it!_

_**

* * *

** _

**The Unquantifiable Variable**  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

**_Chapter Eight_**

At a nod from Don, Jacobsen picked up the phone and dialed. Don stepped out of the van, knowing the negotiator would do his job. He adjusted his earpiece and concentrated on the information flowing at him.

"Shooter Two; there's movement inside."

"Entry Team; we're in back and in position."

"Driver," Terry announced herself. "Car is in position and waiting for 'go'."

"Shooter One; I see two people inside, no threatening moves."

"Shooters," Don directed, "you're on yellow." If they saw Jason move to kill Charlie or one of the team, they'd fire immediately. If Jason made no move, they'd wait. Unless Don called green. And any time Don had ever been involved with sharpshooters given green, the target was usually dead before the word was completely spoken.

* * *

Inside the store, Charlie picked up the phone. He listened for a moment, then held it out to the gunman. "They want to talk to you." 

The gunman took the phone and held it to his ear with his left hand, his right holding the pistol. "Do you have the car?" he asked. Silence. "No. I want the car, or the professor gets it in the head."

Charlie winced. How could the man talk so calmly about killing him? How could it be so easy for him? He inched backwards a step and bumped into the flashlight display. It seemed years since he'd been trying to make the decision between the green one and the blue one. A voice came back to him. _Just don't shine it in someone's eyes._

He slipped one off the rack and hid it in his hand. Not much of a weapon, but maybe there'd be a chance to do something.

"How did you know that?" yelled the gunman into the phone. "How did you know my name is Jason? My brother talked, didn't he? He told you my name – he told you everything!"

Charlie tried taking another step toward the door while the gunman – Jason – was distracted, putting as much clutter between them as possible, but Jason spun and pointed his gun at him. His hand was shaking so badly that Charlie was sure he was dead, whether or not Jason intended to pull the trigger.

"No!" he howled into the phone. "I'm leaving, and I'm taking the professor with me. You better have that car out front when we come out, or he's dead, and I'll take as many of you with us as I can."

The probability of survival under the current system hit zero. No choices now. Even if he ran, he would probably die. But if he stayed, he would definitely die. He ran.

* * *

"Don!" Terry's voice came through his earpiece loud and clear. "I see Charlie – he's trying to run for it." 

"Don, he's gone off the deep end." Pete Jacobsen's voice followed hard on Terry's.

_Oh, shit!_ thought Don. "Nolan; execute, execute, execute!"

David flung the back door open and piled in, breaking left. His teammate headed to the right, and they ran up the aisles, Nolan and his people right behind them.

* * *

Jason ran after Charlie and grabbed him by the shirt. They both flew forward into the entranceway to the store, first Jason on top, then Charlie, a tumbling heap of flying arms and legs. Charlie tried to pull himself loose, but Jason had a madman's grip on his clothes. Charlie felt his shirt pull down around his arms, and he pulled them loose from the sleeves, but Jason had grabbed enough cloth to get the t-shirt underneath as well. He yanked, and Charlie went down again, hitting his head hard against the floor. Dazed, he felt himself lifted and before he could get his arms and legs moving again, his air was cut off at the throat, and he felt something very hard pushing into the side of his head. 

"Get back!"

Charlie realized he was standing, though the only thing holding him up was the arm around his neck. He pulled at it, but Jason had the strength of a man driven mad.

"Get back, or I'll kill him!"

They were outside, and as Jason turned to find an escape, Charlie saw the rescue team coming out of the store behind them, then a car with Terry behind the wheel, and finally, in front of them was the rest of the FBI team with their weapons pointed straight at him – including Don.

* * *

Don's eyes widened as he took in all the implications of the situation in front of him. Charlie looked half out of it, fresh blood streaming from the gash in his forehead. Jason was literally holding him up, dragging him along like a doll. His right hand pushed a gun into Charlie's head, and there was no chance that a shot at him could disable him fast enough for it not to go off. His left arm was crooked around Charlie's neck, and he looked like he had something in his hand. 

"Can anyone see what he's got in his left hand," he called into his mike.

"Grenade," came the voice he recognized as Shooter Two. "And the pin is out."

Don was beyond swearing. They'd done everything right, and it still had blown up in their faces. He pushed down all feelings, all his fear for his brother, and with a swift, silent plea, did what he had to. "Jason!" he called out, his pistol pointed right at the gunman's head. "Put the weapon down! You're not getting out of this, so drop the gun. Drop it now, Jason; drop the gun."

"You won't shoot – you'll hit the professor." His voice was on the edge of hysteria.

"I will shoot," Don yelled back as he gradually stepped forward. "I can't let you go, even if you kill my brother and everyone else here. I will not let you go, so put the gun down."

Jason's eyes narrowed, and his attention focused on Don. "You! You're the one who's done all this. You're the one took my brother from me— Well, now you won't have a brother either!"

"Your brother's not dead!"

Voice rising, he screamed, "Yes, he is – he's dead to me, just like my buddies, my girl – you took everyone from me, and now I'm gonna take your brother away from you!"

Don spoke quietly into his mike. "Shooters, if he so much as twitches that gun an inch away, go green."

Terry's voice spoke in his ear. "He's focusing all his problems on you, Don, making you the scapegoat for everything that's gone wrong in his life. You might be able to distract him enough for Charlie to get loose if you do it soon."

He knew what she was saying – his brother was heaving for air, eyes closed, nearly limp except for one hand that pulled uselessly at the arm around his neck.

"Jason," he said, taking another step forward. "It's not Charlie's fault. He's just my little brother. Don't punish him for what he hasn't done. Let him go, and we'll work this out."

Jason's eyes flitted from Don to the car and back.

"Terry," Don said quietly, carefully not looking at her, "get out of the car on the passenger side. Get out, now."

And then, as if in slow motion, Don saw Charlie raise his right hand. He squeezed, Jason's right eye was suddenly illuminated and he recoiled, letting go of Charlie, who slipped out from under his arm and staggered to the right. Two shots fired immediately, Jason jerked back against the building, and he flung his arms out. The grenade flew out of his hand and then the world blew to hell.

* * *

The blast knocked Don off his feet, but he hit the ground rolling and came up a little dazed, but standing. As the smoke blew in wisps around him, he saw Jason dead on the ground with a bullet through his head. He cast wildly around for his brother. A gust cleared and he saw two bodies on the sidewalk – one a petite policewoman, the other, his brother. Neither were moving. He ran to them, sliding to his knees the same time as Nolan. The girl was moaning, and Nolan called for paramedics. Charlie lay crumpled against the pallets of grass seed, motionless, his eyes open and staring. 

"No," moaned Don. He rested one hand on Charlie's chest and pushed two fingers against his neck, feeling for any sign of life. Nothing. No movement. He shifted his fingers, pushed harder. "Oh, God, don't do this – please, don't do this."

And then he saw Charlie blink.

He cradled his brother's head in one hand. "Charlie – are you there, buddy? Can you hear me?"

His brother's chest heaved in a convulsive gasp for air, once, twice, and then a blessed, weak voice said, "Don?"

Don's heart dropped back into place; tears flooded his eyes and choked him. He dropped his forehead to touch his brother's. "Yeah, buddy. I'm here."

* * *


	18. Epilogue

**_The Unquantifiable Variable_**  
_By Becky Sims  
April, 2005_

_  
The Eppes family and the characters and situations from the TV show "NUMB3RS" are the property of the Scotts and the creation of Cheryl Heuton and Nick Falacci. No infringement is intended, and no profit is being made. _

_**Epilogue**_

"They gave me a cane so I could do it myself," came an irritated voice from just outside the front door of the Eppes house late that evening.

Alan rushed to open it for his two sons, the larger of whom was trying to get the shorter to lean on him. Charlie's bloodsoaked jeans had been cut off and disposed of at the emergency room, and he was now wearing a baggy pair of designer sweats Alan had gotten from the store across the street from the hospital. A small bandage completely covered the few stitches in his son's forehead, but the lines between his eyes hinted at a vicious headache.

Don groaned in exasperation. "Charlie, you could barely walk from the hospital to the car, you're so sore."

"I rested up while you were driving. Now let me walk into the house on my own two feet before we scare Dad—"

"Too late," Alan said. "And believe me, I'm nowhere near as scared as I was this afternoon when I saw that grenade go off." By the grace of God, his eldest's training and his youngest's quick thinking, he hadn't lost both his boys. He swallowed and got his voice back under control. "I don't think either one of you will ever be able to give me another gray hair."

"That's because I'm gonna get 'em all," said Don.

His comment rated only a withering glance from Charlie, a sure sign to Alan that he really wasn't as well as he was pretending. He held the door open for his sons. "I don't understand why that doctor didn't keep you in the hospital at least overnight," he fussed as they made their way slowly through the living room.

"I didn't want him to," answered Charlie. He stopped in the entrance to the family room, heaved a deep sigh and visibly relaxed. "I wanted to be home."

Alan eyed him carefully, still worried that his youngest was more severely injured than he was letting on.

Don just shook his head. "I asked the doc again, after you left, Dad, just to make sure. He said that since Charlie didn't have a concussion or any broken bones, miracle of miracles, he just needed rest."

"And I can do that here as well as at the hospital. Better, actually." He headed for the couch, then simply stood in front of it. "But I think I'm going to need a little help."

They were at his side in an instant, and with one hanging on to each arm, he lowered himself carefully. Once seated, he tilted his head back and exhaled in relief. Don lifted his injured leg up onto the cushions, piling a couple pillows under the knee to support it.

"What about that officer?" Alan asked. "The girl who jumped between Charlie and the explosion. Will she be okay?"

"In time," Don said. "She took the brunt of the blast, but had protective gear so she wasn't hurt too bad." He didn't add that without it, neither she nor Charlie would have survived. He had every intention of visiting her in a day or so to thank her . . . and see if she was interested in a career change.

Alan studied his younger son. "Well, Amita's in the kitchen, watching over the soup and making tea. Strange prescription for a doctor to give out, though your mother would certainly have approved. Do you want it here or at the table?"

"Thanks, Dad, but I think I'd better stay put for now. Don, do you have those pills?"

Don patted his pockets until he located the small bottle he'd been given by the doctor. "Let me get you a glass of water."

Amita handed him one as soon as he walked into the kitchen, along with a bottle of over-the-counter headache pills as well. "For you," she said.

He grinned and rubbed at his forehead. "Thanks. And I'll take a bowl of that soup, too. What is it?" He swallowed a couple of the pills, drinking the entire glass of water without stopping.

"I don't know what it's called, but your father said it was something your mother used to make. Comfort food, as the doctor ordered."

Don sniffed appreciatively, and the familiar aroma brought back happy memories that did more to ease his headache than the pills probably would. "He meant it literally. Charlie's still pretty shaken up – I could feel him trembling all the way into the house. He's never had that kind of force used against him before; his body doesn't know how to react. Home, good food, friends, his own bed – he'll settle down a lot faster."

"You sound like you know," she commented as she dished up the soup.

"In football, we called it getting into hitting shape. You had to get used to being pummeled every training season. First few days, you'd go home so sore you'd swear you'd never be able to move again. Pretty soon, though, it passes off. This is Charlie's first time getting physically knocked around like that, on top of everything he went through inside. It's gonna take a little time."

He dropped a spoon in one of the bowls, then grabbed it and Charlie's glass of water and headed back out. He parked himself at the table, but Amita eased herself down onto the floor next to Charlie. She held the bowl up in easy reach, but gave him the spoon.

Charlie dipped into it. "Mom's soup." He tasted it, and looked up at his father with a smile. "It's just right. Thanks."

Alan nodded, then with quick strides, headed for the kitchen. Amita murmured something to Charlie, but Don got up and followed his father.

"Dad?" he asked.

Alan was standing over the sink, head bowed. "I thought . . . this afternoon, I thought I'd never see that smile again, I'd never hear his voice—" He turned and Don saw the tears in his eyes. "Thank you."

There wasn't anything Don could say that would be right. He knew what he could have done better, he knew it was just his job, but he also knew that he had to let his father say it. So he simply gathered him in his arms and said, "You're welcome."

* * *

When they returned to the dining room, it was to discover that Charlie had fallen asleep. Amita still sat on the floor next to him, leafing through a ragged pile of yellow legal-size sheets of paper.

"What're those?" Alan asked.

"Detective Nolan gave them to me to sort through. He said they were papers Charlie had been writing on. He didn't know if any of them related to the other case you guys were working on. He wants them back, if he can have them, to help complete his report."

"And?" said Don.

She shuffled them into three piles and pointed at the biggest one. "These are just doodles. Odd thoughts, nothing significant. These—" and she pointed to the second, smaller pile of about four sheets, "—look like the equations I've seen him working on lately. We should set them aside until we can ask him if he needs them." She picked up one last lone paper. "And this is an entropy chart."

Alan studied it. "Judging by the working over it's had, I'd say it was pretty important." He turned to Don. "Better keep that one safe. It might be critical to your case."

But Amita didn't pass it to him. "Actually, it's a record of this afternoon."

"What?" Don gave her a hand up and led her over to the table. She laid it down and gently smoothed the wrinkles out of it.

"Look here – the lines up and down are indicators of time passing. Here's the ascending arc that shows the progress towards chaos before the injured men are released, and then it drops down suddenly. It begins to rise again, then spikes when Jason took off his mask and Charlie talked him into releasing Leeda and Solana. It drops, but not as far. See these dots here? That's Charlie explaining it to Jason, poking at it with his pen. He's demonstrating how the system is headed toward chaos if the variables aren't reduced."

Don and Alan blinked at each other. Sure enough, it matched perfectly. "I think Nolan's really going to want a copy of this," Don muttered.

"What I don't understand," Amita said, "is why the change variable increases in value so much at the end. Looking at this chart, the system should have degenerated into complete chaos, yet because of this variable, it didn't."

"Which one is that?" Alan asked.

Amita pointed at the series of triangles that ran along the bottom of the page, one per time segment. "Something happened about here – you can see he was darkening that one on the right over and over." She shook her head. "Well, we won't get an answer out of him tonight. I'd better get home and get to bed, too." She rose and found her purse. "Would you call me when he wakes up? I guess I'd just like to know . . ."

Alan put an arm around her shoulders and guided her toward the door. "Of course I will." His voice faded as he walked her out to her car.

Don studied his brother, who had also fallen asleep on the examining table at the hospital, scaring the remaining years off his life. When Don had finished with the insurance paperwork and found his way to the cubicle where Charlie lay, he'd discovered one doctor bent over Charlie stitching the cut over his eye, a nurse wrapping gauze around his brother's swollen knee and leg, and Charlie looking like he was out cold. He'd woken at Don's feather touch, though, and smiled. And Don had finally begun to believe he'd be all right.

Don knew he couldn't leave Charlie on the couch, but was reluctant to wake him. He finally sighed and murmured his brother's name.

"Mmm?" Charlie answered.

"C'mon, buddy." He gently swung his brother's leg to the floor, got an arm behind his shoulders and gently lifted him to his feet.

"Bed?" Charlie murmured. His eyes were still closed, but he stood on his own.

Don nudged him forward a little at a time. "Yeah, I think you'll feel better if you sleep stretched out. You're going to be sore enough in the morning without adding in the extra kinks you'd get from sleeping on the couch." They made it to the stairs, and Don took a little more of his brother's weight to help him up the steps. He remembered times he'd had to do the same when Charlie had stayed up too late working on his homework for school – back then, it was because of his passionately seeking mind that lived in a body that still had a child's limitations. Charlie still pushed his physical limitations when he was on the trail of a problem, but never before had he had to do it to save his life.

Don settled him on the bed, pulled off his sweatpants and gave him a clean t-shirt – the one he was wearing still had spots of blood on it – and tucked him under the covers. It was only when he sat down in the creaky chair next to the bed that Charlie blinked open his eyes.

"Don?" His voice was soft and sleepy.

Don leaned forward, elbows on his knees. "Yeah, buddy?"

"You staying?"

He had a flashback to the pleading of a boy afraid of the monsters in the closet, a boy who believed his big brother could slay any danger.

He smiled. "For a little bit. Then I'll bet Dad'll be up here and drag me into the solarium for more soup. We'll be close by if you need us."

"'kay," Charlie mumbled. His lids drooped, but then he roused again. "Don?"

"Go to sleep," Don commanded softly.

Instead, Charlie blinked a few times as if to clear his vision and bring himself back out of his deep weariness. "The triangles are delta," he said. "For Don. The variable that changed the equation to the possible." Then he smiled and gave up the battle to stay awake. His eyes fluttered shut again, his body slowly relaxed, and his breathing deepened.

And Don continued to sit by his side, guarding his brother's dreams and wondering over a mind that had found a way to add that most unquantifiable variable of all to an equation – love.

_**The End**_

* * *


End file.
